source_code: import java.io.BufferedWriter;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.io.Writer;
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.InputMismatchException;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.Random;
  import java.util.TreeSet;
  
  /**
   * Actual solution is at the top, in class Solver
   */
  public class Main implements Runnable {
  	private static String[] args;
  
  	public static void main(String[] args) {
  		Main.args = args;
  		new Thread(null, new Main(), "MyRunThread", 1 << 26).start();
  	}
  
  	@Override
  	public void run() {
  		long time_beg = -1;
  		InputStream inputStream = System.in;
  		OutputStream outputStream = System.out;
  		if (args.length > 0 && args[0].equals("outside")) {
  			time_beg = System.currentTimeMillis();
  			try {
  				inputStream = new FileInputStream("IO/in.txt");
  //				outputStream = new FileOutputStream("IO/out.txt");
  			} catch (Exception e) {
  				System.err.println(e);
  				System.exit(1);
  			}
  		} else {
  			try {
  //				inputStream = new FileInputStream("file_name");
  //				outputStream = new FileOutputStream("file_name");
  			} catch (Exception e) {
  				System.err.println(e);
  				System.exit(1);
  			}
  		}
  
  		Solver s = new Solver();
  		s.in = new InputReader(inputStream);
  		s.out = new OutputWriter(outputStream);
  		if (args.length > 0 && args[0].equals("outside")) {
  			s.debug = new DebugWriter(s.out);
  		}
  
  		s.solve();
  		s.out.close();
  
  		if (args.length > 0 && args[0].equals("outside")) {
  			s.debug.close();
  			System.err.printf("*** Total time: %.3f ***\n", (System.currentTimeMillis() - time_beg) / 1000.0);
  		}
  	}
  }
  
  final class Solver {
  	InputReader in;
  	OutputWriter out;
  	DebugWriter debug;
  
  	public void solve() {
  		int n = in.readInt();
  		int[] mas = new int[n];
  		int[] sorted = new int[n];
  		
  		for (int i = 0; i < n; ++i)
  			sorted[i] = mas[i] = in.readInt();
  
  		Random rnd = new Random(System.nanoTime());
  		for (int i = 1; i < n; ++i) {
  			int j = rnd.nextInt(i);
  			int tmp = sorted[j];
  			sorted[j] = sorted[i];
  			sorted[i] = tmp;
  		}
  
  		Arrays.sort(sorted);
  
  		int id1 = -1;
  
  		for (int i = 0; i < n; ++i)
  			if (mas[i] != sorted[i]) {
  				id1 = i;
  				break;
  			}
  
  		int id2 = -1;
  
  		for (int i = n - 1; i >= 0; --i)
  			if (mas[i] != sorted[i]) {
  				id2 = i;
  				break;
  			}
  
  		if (id1 != -1 && id2 != -1 && id1 != id2) {
  			int tmp = mas[id1];
  			mas[id1] = mas[id2];
  			mas[id2] = tmp;
  		}
  
  		for (int i = 0; i < n; ++i)
  			if (mas[i] != sorted[i]) {
  				out.printLine("NO");
  				return;
  			}
  		out.printLine("YES");
  	}
  }
  class InputReader {
  	private boolean finished = false;
  
  	private InputStream stream;
  	private byte[] buf = new byte[1024];
  	private int curChar;
  	private int numChars;
  
  	public InputReader(InputStream stream) {
  		this.stream = stream;
  	}
  
  	private int read() {
  		if (numChars == -1)
  			throw new InputMismatchException();
  		if (curChar >= numChars) {
  			curChar = 0;
  			try {
  				numChars = stream.read(buf);
  			} catch (IOException e) {
  				throw new InputMismatchException();
  			}
  			if (numChars <= 0)
  				return -1;
  		}
  		return buf[curChar++];
  	}
  
  	public int peek() {
  		if (numChars == -1)
  			return -1;
  		if (curChar >= numChars) {
  			curChar = 0;
  			try {
  				numChars = stream.read(buf);
  			} catch (IOException e) {
  				return -1;
  			}
  			if (numChars <= 0)
  				return -1;
  		}
  		return buf[curChar];
  	}
  
  	public int readInt() {
  		int c = read();
  		while (isSpaceChar(c))
  			c = read();
  		int sgn = 1;
  		if (c == '-') {
  			sgn = -1;
  			c = read();
  		}
  		int res = 0;
  		do {
  			if (c < '0' || c > '9')
  				throw new InputMismatchException();
  			res *= 10;
  			res += c - '0';
  			c = read();
  		} while (!isSpaceChar(c));
  		return res * sgn;
  	}
  
  	public long readLong() {
  		int c = read();
  		while (isSpaceChar(c))
  			c = read();
  		int sgn = 1;
  		if (c == '-') {
  			sgn = -1;
  			c = read();
  		}
  		long res = 0;
  		do {
  			if (c < '0' || c > '9')
  				throw new InputMismatchException();
  			res *= 10;
  			res += c - '0';
  			c = read();
  		} while (!isSpaceChar(c));
  		return res * sgn;
  	}
  
  	public String readString() {
  		int c = read();
  		while (isSpaceChar(c))
  			c = read();
  		StringBuilder res = new StringBuilder();
  		do {
  			res.appendCodePoint(c);
  			c = read();
  		} while (!isSpaceChar(c));
  		return res.toString();
  	}
  
  	public static boolean isSpaceChar(int c) {
  		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
  	}
  
  	private String readLine0() {
  		StringBuilder buf = new StringBuilder();
  		int c = read();
  		while (c != '\n' && c != -1) {
  			if (c != '\r')
  				buf.appendCodePoint(c);
  			c = read();
  		}
  		return buf.toString();
  	}
  
  	public String readLine() {
  		String s = readLine0();
  		while (s.trim().length() == 0)
  			s = readLine0();
  		return s;
  	}
  
  	public String readLine(boolean ignoreEmptyLines) {
  		if (ignoreEmptyLines)
  			return readLine();
  		else
  			return readLine0();
  	}
  
  	public BigInteger readBigInteger() {
  		try {
  			return new BigInteger(readString());
  		} catch (NumberFormatException e) {
  			throw new InputMismatchException();
  		}
  	}
  
  	public char readCharacter() {
  		int c = read();
  		while (isSpaceChar(c))
  			c = read();
  		return (char) c;
  	}
  
  	public double readDouble() {
  		int c = read();
  		while (isSpaceChar(c))
  			c = read();
  		int sgn = 1;
  		if (c == '-') {
  			sgn = -1;
  			c = read();
  		}
  		double res = 0;
  		while (!isSpaceChar(c) && c != '.') {
  			if (c == 'e' || c == 'E')
  				return res * Math.pow(10, readInt());
  			if (c < '0' || c > '9')
  				throw new InputMismatchException();
  			res *= 10;
  			res += c - '0';
  			c = read();
  		}
  		if (c == '.') {
  			c = read();
  			double m = 1;
  			while (!isSpaceChar(c)) {
  				if (c == 'e' || c == 'E')
  					return res * Math.pow(10, readInt());
  				if (c < '0' || c > '9')
  					throw new InputMismatchException();
  				m /= 10;
  				res += (c - '0') * m;
  				c = read();
  			}
  		}
  		return res * sgn;
  	}
  
  	public boolean isExhausted() {
  		int value;
  		while (isSpaceChar(value = peek()) && value != -1)
  			read();
  		return value == -1;
  	}
  }
  
  class OutputWriter {
  	private final PrintWriter writer;
  
  	public OutputWriter(OutputStream outputStream) {
  		writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
  	}
  
  	public OutputWriter(Writer writer) {
  		this.writer = new PrintWriter(writer);
  	}
  
  	public void print(Object... objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(Object... objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printFormat(String format, Object... objects) {
  		writer.printf(format, objects);
  	}
  
  
  	public void print(char[] objects) {
  		writer.print(objects);
  	}
  
  	public void printLine(char[] objects) {
  		writer.println(objects);
  	}
  
  	public void printLine(char[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void print(int[] objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(int[] objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printLine(int[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void print(long[] objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(long[] objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printLine(long[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void print(double[] objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(double[] objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printLine(double[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void print(byte[] objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(byte[] objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printLine(byte[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void print(boolean[] objects) {
  		for (int i = 0; i < objects.length; i++) {
  			if (i != 0)
  				writer.print(' ');
  			writer.print(objects[i]);
  		}
  	}
  
  	public void printLine(boolean[] objects) {
  		print(objects);
  		writer.println();
  	}
  
  	public void printLine(boolean[][] objects) {
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  	}
  
  
  	public void close() {
  		writer.close();
  	}
  
  	public void flush() {
  		writer.flush();
  	}
  }
  
  class DebugWriter {
  	private final OutputWriter writer;
  
  	public DebugWriter(OutputWriter writer) {
  		this.writer = writer;
  	}
  
  	private void printDebugMessage() {
  		writer.print("debug:\t");
  	}
  
  
  	public void printLine(Object... objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printFormat(String format, Object... objects) {
  		flush();
  		printDebugMessage();
  		writer.printFormat(format, objects);
  		flush();
  	}
  
  
  	public void printLine(char[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(char[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void printLine(double[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(double[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void printLine(int[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(int[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void printLine(long[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(long[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void printLine(byte[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(byte[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void printLine(boolean[] objects) {
  		flush();
  		printDebugMessage();
  		writer.printLine(objects);
  		flush();
  	}
  
  	public void printLine(boolean[][] objects) {
  		flush();
  		for (int i = 0; i < objects.length; ++i)
  			printLine(objects[i]);
  		flush();
  	}
  
  
  	public void flush() {
  		writer.flush();
  	}
  
  	public void close() {
  		writer.close();
  	}
  }
  