#include <bits/stdc++.h>
      
#define FOR(i,a,b) for( ll i = (a); i < (ll)(b); i++ )
#define REP(i,n) FOR(i,0,n)
#define YYS(x,arr) for(auto& x:arr)
#define ALL(x) (x).begin(),(x).end()
#define SORT(x) sort( (x).begin(),(x).end() )
#define REVERSE(x) reverse( (x).begin(),(x).end() )
#define UNIQUE(x) (x).erase( unique( ALL( (x) ) ) , (x).end() )
#define PW(x) (1LL<<(x))
#define SZ(x) ((ll)(x).size())
#define SHOW(x) cout << #x << " = " << x << endl
#define SHOWA(x,n) for( int i = 0; i < n; i++ ){ cout << x[i] << " "; } cout << endl

#define pb emplace_back
#define fi first
#define se second
     
using namespace std;

typedef long double ld;
typedef long long int ll;
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<bool> vb;
typedef vector<ld> vd;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<vpl> gr;
typedef vector<vl> ml;
typedef vector<vd> md;
typedef vector<vi> mi;
     
const ll INF = (ll)1e9 + 10;
const ll INFLL = (ll)1e18 + 10;
const ld EPS = 1e-12;
const ll MOD = 1e9+7;
     
template<class T> T &chmin( T &a , const T &b ){ return a = min(a,b); }
template<class T> T &chmax( T &a , const T &b ){ return a = max(a,b); }
template<class T> inline T sq( T a ){ return a * a; }

ll in(){ ll x; scanf( "%lld" , &x ); return x; }
char yuyushiki[1000010]; string stin(){ scanf( "%s" , yuyushiki ); return yuyushiki; }

// head


struct Mod{
  unsigned n;
  Mod() : n(0){}
  Mod( ll x ){
    if( x < 0 ) n = x%MOD+MOD;
    else n = x%MOD;
  }
};
Mod operator + ( Mod a  , Mod b ){ return Mod( a.n + b.n ); }
Mod operator +=( Mod &a , Mod b ){ return a = a + b; }
Mod operator - ( Mod a ){ return Mod( MOD - a.n ); }
Mod operator - ( Mod a  , Mod b ){ return Mod( a.n + MOD - b.n ); }
Mod operator -=( Mod &a , Mod b ){ return a = a - b; }
Mod operator * ( Mod a  , Mod b ){ return Mod( (ll)a.n * b.n ); }
Mod operator *=( Mod &a , Mod b ){ return a = a * b; }
Mod modpow( Mod x , ll k ){
  Mod res = 1;
  while( k ){
    if( k & 1 ) res *= x;
    k /= 2;
    x *= x;
  }
  return res;
}
ll extgcd( ll a , ll b , ll &x , ll &y ){
  ll d = a;
  if( b != 0 ){
    d = extgcd( b , a % b , y , x );
    y -= a / b * x;
  } else {
    x = 1, y = 0;
  }
  return d;
}
Mod inv( Mod a ){ ll x, y; assert( extgcd( a.n , MOD , x , y ) == 1 ); return Mod( x ); }
Mod operator / ( Mod a  , Mod b ){ return Mod( (ll)a.n * inv(b).n ); }
Mod operator /=( Mod &a , Mod b ){ return a = a / b; }


int n, m;
string s;

int sum[3010];
int to[3010];

Mod dp[3010][3010];

int main(){

  n = in();
  m = in();
  s = stin();

  sum[0] = 0;
  REP( i , n ){
    sum[i+1] = sum[i] + ( s[i] == '1' ? 1 : 0 );
  }

  // SHOWA( sum , n+1 );
  
  REP( i , n ){
    to[i] = i + 1;
  }
  to[n] = n;
  
  REP( i , m ){
    int l = in() - 1;
    int r = in();
    chmax( to[l] , r );
  }

  REP( i , n ){
    chmax( to[i+1] , to[i] );
  }

  // SHOWA( to , n+1 );

  dp[0][ sum[ to[0] ] ] = 1;

  REP( i , n ){
    REP( j , n+1 ){
      int ne = j + sum[ to[i+1] ] - sum[ to[i] ];
      
      // one
      if( j > 0 ){
	dp[i+1][ne-1] += dp[i][j];
      }

      // zero
      if( to[i] - i - j > 0 ){
	dp[i+1][ne] += dp[i][j];
      }
    }
  }

  /*
  REP( i , n+1 ){
    REP( j , n+1 ){
      cout << dp[i][j].n <<  " ";
    }
    cout << endl;
  }
  */
  
  cout << dp[n][0].n << endl;
  
  return 0;
}


Measured memory_bytes: 35712