#include <bits/stdc++.h>
using namespace std;
const int N = 3005, MOD = 1e9 + 7;

int n, m, r[N], rightend[N], cnt1[N], f[N][N];
string s;

int main() {
  ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
  cin >> n >> m >> s;
  int curl, curr;
  cin >> curl >> curr;
  for (int i = 2, nxl, nxr; i <= m; ++i) {
    cin >> nxl >> nxr;
    if (curl == nxl) curr = max(curr, nxr);
    else if (curr < nxr) {
      r[curl] = curr;
      curl = nxl; curr = nxr;
    }
  }
  r[curl] = curr;
  for (int i = 1; i <= n; ++i) {
    cnt1[i] = cnt1[i - 1] + (s[i - 1] == '1');
    rightend[i] = max(rightend[i - 1], r[i - 1]);
    r[i] = max({r[i], i, rightend[i]});
  }
  f[0][0] = 1;
  for (int i = 0; i <= n; ++i) {
    for (int j = 0; j <= n; ++j) {
      if (f[i][j] == 0) continue;
      int one = j + ((rightend[i] < r[i]) ? (cnt1[r[i]] - cnt1[rightend[i]]) : 0);
      if (one) (f[i + 1][one - 1] += f[i][j]) %= MOD;
      if (r[i] - i + 1 > one) (f[i + 1][one] += f[i][j]) %= MOD;
    }
  }
  cout << f[n + 1][0];
  return 0;
}