#include <bits/stdc++.h>
#define int long long 
using namespace std;

const int N = 3000 + 7, mod = 1e9 + 7;

int c[N], l[N], r[N], n, m, dp[N][N];

string str;


int f(int idx, int one) {
	if(idx > n) {
		return 1;
	}
	if(~dp[idx][one]) {
		return dp[idx][one];
	}
	int res = 0;
	if(r[idx] - idx >= one) {
		if(l[idx + 1] != l[idx]) { 
			res += f(idx + 1, one + c[r[idx + 1]] - c[r[idx]]); 
			res %= mod;
		} else {
			res += f(idx + 1, one);
			res %= mod;
		}
	}

	if(one) {
		if(l[idx + 1] != l[idx]) {
			res += f(idx + 1, one - 1 + c[r[idx + 1]] - c[r[idx]]);
			res %= mod;
		} else {
			res += f(idx + 1, one - 1);
			res %= mod;
		}
	}
	
	return dp[idx][one] = res;
}

int32_t main() {
	ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);

	cin >> n >> m >> str;
	for(int i = 1; i <= m; i++) {
		int lx, rx; cin >> lx >> rx;
		r[lx] = max(rx, r[lx]);
	}

	for(int i = 1; i <= n; i++) {
		r[i] = max(i, r[i]);
		l[i] = r[l[i - 1]] >= r[i] ? l[i - 1] : i;
		r[i] = r[l[i]];
		c[i] = c[i - 1] + (str[i - 1] == '1');
	}

	c[n + 1] = c[n];

	l[n + 1] = r[n + 1] = n + 1;

	memset(dp, -1, sizeof dp);
	cout << f(1, c[r[1]]) << endl;
}