#include <cstdio>

#include <cstring>

#include <algorithm>

using namespace std;

typedef long long ll;

const ll mod = 1000000007;

ll a[110][110] , p[1010] , v[1010];

ll pow(ll x , ll y)

{

	ll ans = 1;

	while(y)

	{

		if(y & 1) ans = ans * x % mod;

		x = x * x % mod , y >>= 1;

	}

	return ans;

}

int main()

{

	int d , w , i , j , k;

	ll t , ans = 0;

	scanf("%d%d" , &d , &w);

	for(i = 1 ; i <= w ; i ++ ) scanf("%lld%lld" , &p[i] , &v[i]);

	if(w == 1 && p[1] == 1)

	{

		puts("1");

		return 0;

	}

	for(i = 1 ; i <= d + 1 ; i ++ )

	{

		a[i][0] = 1;

		for(j = 1 ; j <= d + 1 ; j ++ ) a[i][j] = a[i][j - 1] * i % mod;

		a[i][d + 2] = (a[i - 1][d + 2] + a[i][d]) % mod;

	}

	for(i = 1 ; i <= d + 1 ; i ++ )

	{

		for(j = i ; j <= d + 1 ; j ++ ) if(a[i][j]) break;

		if(j > d + 1) continue;

		for(k = i ; k <= d + 2 ; k ++ ) swap(a[i][k] , a[j][k]);

		t = pow(a[i][i] , mod - 2);

		for(j = i ; j <= d + 2 ; j ++ ) a[i][j] = a[i][j] * t % mod;

		for(j = 1 ; j <= d + 1 ; j ++ )

			if(j != i)

				for(t = a[j][i] , k = i ; k <= d + 2 ; k ++ )

					a[j][k] = (a[j][k] - a[i][k] * t % mod + mod) % mod;

	}

	for(i = 1 ; i <= d + 1 ; i ++ )

	{

		t = 1;

		for(j = 1 ; j <= w ; j ++ )

			t = t * pow(pow(p[j] , v[j]) , i) % mod * (1 - pow(p[j] , (d - i + mod - 1) % (mod - 1)) + mod) % mod;

		ans = (ans + a[i][d + 2] * t) % mod;

	}

	printf("%lld\n" , ans);

	return 0;

}