#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#include<map>
using namespace std;
typedef long long ll;
#define N 1000015
const int p=1e9+7;
int n,m,dp[3002][3002],mx[N],s[N];
char ch[N];
inline int ksm(int d,int tk){int ret=1;while(tk){if(tk&1)ret=1ll*ret*d%p;d=1ll*d*d%p;tk>>=1;}return ret;}
int main()
{
    scanf("%d%d",&n,&m);
    scanf("%s",ch+1);
    for(int i=1;i<=n;i++)s[i]=s[i-1]+ch[i]-'0',mx[i]=i;s[n+1]=s[n];
    for(int i=1;i<=m;i++)
    {
    	int l,r;scanf("%d%d",&l,&r);
    	mx[l]=max(mx[l],r);
	}
	for(int i=1;i<=n;i++)mx[i]=max(mx[i],mx[i-1]);mx[n+1]=mx[n];
	dp[0][s[mx[1]]]=1;
	for(int i=0;i<n;i++)for(int j=0;j<=n;j++)
	{
		if(j)(dp[i+1][j+s[mx[i+2]]-s[mx[i+1]]-1]+=dp[i][j])%=p;
		if(mx[i+1]-i-j>0)(dp[i+1][j+s[mx[i+2]]-s[mx[i+1]]]+=dp[i][j])%=p;
	}
	printf("%d\n",dp[n][0]);
}
