#include<iostream>
#include<string.h>
#include<stdio.h>
#include<map>
#include<vector>
#include<queue>
#include<stack>
#include<math.h>
#include<set>
#include<bitset>
#include<deque>
#include<unordered_map>
#include<algorithm>
#define int long long
using namespace std;
typedef pair<int,int>PII;
const int N=1e5+10,M=5e2+10;
const int mod=1e9+7;
int n,m;
vector<int>v[N];
int sum[N],ru[N];
int ans;

struct le{
	int a,b;
}ll[N];

signed main(){
	ios::sync_with_stdio(false);
	cin.tie();
	cout.tie();
	while(cin>>n>>m){
		for(int i=1;i<=n;i++){
			cin>>ll[i].a>>ll[i].b;
			sum[i]=ll[i].a;
			ru[i]=0;
			v[i].clear();
		}
		for(int i=1;i<=m;i++){
			int x,y;
			cin>>x>>y;
			v[x].push_back(y);
			ru[y]++;
		}
		queue<int>q;
		for(int i=1;i<=n;i++){
			if(ru[i]==0) q.push(i);
		}
		ans=0;
		while(!q.empty()){
			int no=q.front();
			q.pop();
			int pp=v[no].size();
			for(int i=0;i<pp;i++){
				int oo=v[no][i];
				ans=(ans+sum[no]*ll[oo].b%mod)%mod;
				sum[oo]=(sum[no]+ll[oo].a)%mod;
				ru[oo]--;
				if(ru[oo]==0) q.push(oo);
			}
		}
//		for(int i=1;i<=n;i++) cout<<sum[i]<<endl;
		cout<<ans<<endl;
	}
	return 0;
}