source_code: import java.math.BigDecimal;
  import java.math.MathContext;
  import java.math.RoundingMode;
  import java.nio.charset.Charset;
  import java.util.*;
  
  import static java.lang.System.gc;
  import static java.lang.System.out;
  
  public class Main {
  
      Scanner scanner = new Scanner(System.in);
  
      public static void main(String[] args) {
          new Main().solve();
      }
  
  
      void solve() {
  
          int n = scanner.nextInt();
          scanner.nextLine();
          String s1 = scanner.nextLine();
          String s2 = scanner.nextLine();
  
  
          int ans = 0;
          boolean a[] = new boolean[30];
          boolean b[] = new boolean[30];
  
          for (int i = 0; i < n; i++) {
              if (s1.charAt(i) != s2.charAt(i)) {
                  ans ++;
                  a[s1.charAt(i)  - 'a'] = true;
                  b[s2.charAt(i)  - 'a'] = true;
              }
          }
          for (int i = 0; i < n; i++) {
              if (s1.charAt(i) != s2.charAt(i) && a[s2.charAt(i) - 'a'] && b[s1.charAt(i) - 'a']) {
                  for (int j = i + 1; j < n; j ++) {
                      if (s1.charAt(i) == s2.charAt(j) && s1.charAt(j) == s2.charAt(i)) {
                          out.println(ans - 2);
                          out.println((i + 1) + " " + (j + 1));
                          return;
                      }
                  }
              }
          }
  
          for (int i = 0; i < n; i++) {
              if (s1.charAt(i) != s2.charAt(i) && (a[s2.charAt(i) - 'a'] || b[s1.charAt(i) - 'a'])) {
                  for (int j = i + 1; j < n; j ++) {
                      if (s1.charAt(j) != s2.charAt(j) && (s1.charAt(i) == s2.charAt(j) || s1.charAt(j) == s2.charAt(i))) {
                          out.println(ans - 1);
                          out.println((i + 1) + " " + (j + 1));
                          return;
                      }
                  }
              }
          }
  
          out.println(ans);
          out.println(-1 + " " + -1);
      }
  }