source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.io.IOException;
  import java.io.UncheckedIOException;
  import java.io.Closeable;
  import java.io.Writer;
  import java.io.OutputStreamWriter;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   */
  public class Main {
      public static void main(String[] args) throws Exception {
          Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 27);
          thread.start();
          thread.join();
      }
  
      static class TaskAdapter implements Runnable {
          @Override
          public void run() {
              InputStream inputStream = System.in;
              OutputStream outputStream = System.out;
              FastInput in = new FastInput(inputStream);
              FastOutput out = new FastOutput(outputStream);
              G2PlaylistForPolycarpHardVersion solver = new G2PlaylistForPolycarpHardVersion();
              solver.solve(1, in, out);
              out.close();
          }
      }
  
      static class G2PlaylistForPolycarpHardVersion {
          Modular mod = new Modular(1e9 + 7);
  
          public void solve(int testNumber, FastInput in, FastOutput out) {
              int n = in.readInt();
              int m = in.readInt();
              int[][] musics = new int[n][2];
              int[] cnts = new int[4];
              for (int i = 0; i < n; i++) {
                  musics[i][0] = in.readInt();
                  musics[i][1] = in.readInt();
                  cnts[musics[i][1]]++;
              }
  
              int c1 = cnts[1];
              int c2 = cnts[2];
              int c3 = cnts[3];
  
              int[][][][] comp = new int[c1 + 1][c2 + 1][c3 + 1][4];
              for (int i = 0; i <= c1; i++) {
                  for (int j = 0; j <= c2; j++) {
                      for (int k = 0; k <= c3; k++) {
                          for (int t = 0; t < 4; t++) {
                              if (i == 0 && j == 0 && k == 0) {
                                  comp[i][j][k][t] = 1;
                                  continue;
                              }
                              if (i > 0 && t != 1) {
                                  comp[i][j][k][t] = mod.plus(comp[i][j][k][t], mod.mul(comp[i - 1][j][k][1], i));
                              }
                              if (j > 0 && t != 2) {
                                  comp[i][j][k][t] = mod.plus(comp[i][j][k][t], mod.mul(comp[i][j - 1][k][2], j));
                              }
                              if (k > 0 && t != 3) {
                                  comp[i][j][k][t] = mod.plus(comp[i][j][k][t], mod.mul(comp[i][j][k - 1][3], k));
                              }
                          }
                      }
                  }
              }
  
              int[][][][] last = new int[c1 + 1][c2 + 1][c3 + 1][m + 1];
              int[][][][] next = new int[c1 + 1][c2 + 1][c3 + 1][m + 1];
  
              last[0][0][0][0] = 1;
              int t1 = 0;
              int t2 = 0;
              int t3 = 0;
              for (int[] music : musics) {
                  int m1 = music[1];
                  int m0 = music[0];
                  if (m1 == 1) {
                      t1++;
                  } else if (m1 == 2) {
                      t2++;
                  } else {
                      t3++;
                  }
                  for (int i = 0; i <= t1; i++) {
                      for (int j = 0; j <= t2; j++) {
                          for (int k = 0; k <= t3; k++) {
                              for (int t = 0; t <= m; t++) {
                                  next[i][j][k][t] = last[i][j][k][t];
                                  if (t < m0) {
                                      continue;
                                  }
                                  if (m1 == 1 && i > 0) {
                                      next[i][j][k][t] = mod.plus(next[i][j][k][t], last[i - 1][j][k][t - m0]);
                                  } else if (m1 == 2 && j > 0) {
                                      next[i][j][k][t] = mod.plus(next[i][j][k][t], last[i][j - 1][k][t - m0]);
                                  } else if (m1 == 3 && k > 0) {
                                      next[i][j][k][t] = mod.plus(next[i][j][k][t], last[i][j][k - 1][t - m0]);
                                  }
                              }
                          }
                      }
                  }
  
                  int[][][][] tmp = last;
                  last = next;
                  next = tmp;
              }
  
              int ans = 0;
              for (int i = 0; i <= c1; i++) {
                  for (int j = 0; j <= c2; j++) {
                      for (int k = 0; k <= c3; k++) {
                          ans = mod.plus(ans, mod.mul(last[i][j][k][m], comp[i][j][k][0]));
                      }
                  }
              }
  
              out.println(ans);
          }
  
      }
  
      static class Modular {
          int m;
  
          public Modular(int m) {
              this.m = m;
          }
  
          public Modular(long m) {
              this.m = (int) m;
              if (this.m != m) {
                  throw new IllegalArgumentException();
              }
          }
  
          public Modular(double m) {
              this.m = (int) m;
              if (this.m != m) {
                  throw new IllegalArgumentException();
              }
          }
  
          public int valueOf(int x) {
              x %= m;
              if (x < 0) {
                  x += m;
              }
              return x;
          }
  
          public int valueOf(long x) {
              x %= m;
              if (x < 0) {
                  x += m;
              }
              return (int) x;
          }
  
          public int mul(int x, int y) {
              return valueOf((long) x * y);
          }
  
          public int plus(int x, int y) {
              return valueOf(x + y);
          }
  
          public String toString() {
              return "mod " + m;
          }
  
      }
  
      static class FastOutput implements AutoCloseable, Closeable {
          private StringBuilder cache = new StringBuilder(10 << 20);
          private final Writer os;
  
          public FastOutput(Writer os) {
              this.os = os;
          }
  
          public FastOutput(OutputStream os) {
              this(new OutputStreamWriter(os));
          }
  
          public FastOutput println(int c) {
              cache.append(c).append('\n');
              return this;
          }
  
          public FastOutput flush() {
              try {
                  os.append(cache);
                  os.flush();
                  cache.setLength(0);
              } catch (IOException e) {
                  throw new UncheckedIOException(e);
              }
              return this;
          }
  
          public void close() {
              flush();
              try {
                  os.close();
              } catch (IOException e) {
                  throw new UncheckedIOException(e);
              }
          }
  
          public String toString() {
              return cache.toString();
          }
  
      }
  
      static class FastInput {
          private final InputStream is;
          private byte[] buf = new byte[1 << 13];
          private int bufLen;
          private int bufOffset;
          private int next;
  
          public FastInput(InputStream is) {
              this.is = is;
          }
  
          private int read() {
              while (bufLen == bufOffset) {
                  bufOffset = 0;
                  try {
                      bufLen = is.read(buf);
                  } catch (IOException e) {
                      bufLen = -1;
                  }
                  if (bufLen == -1) {
                      return -1;
                  }
              }
              return buf[bufOffset++];
          }
  
          public void skipBlank() {
              while (next >= 0 && next <= 32) {
                  next = read();
              }
          }
  
          public int readInt() {
              int sign = 1;
  
              skipBlank();
              if (next == '+' || next == '-') {
                  sign = next == '+' ? 1 : -1;
                  next = read();
              }
  
              int val = 0;
              if (sign == 1) {
                  while (next >= '0' && next <= '9') {
                      val = val * 10 + next - '0';
                      next = read();
                  }
              } else {
                  while (next >= '0' && next <= '9') {
                      val = val * 10 - next + '0';
                      next = read();
                  }
              }
  
              return val;
          }
  
      }
  }
  
  