//#include <bits/stdc++.h>
#include<cstdio>  
#include<cstring>  
#include<algorithm>  
#include<iostream>  
#include<string>  
#include<vector>  
#include<stack>  
#include<bitset>  
#include<cstdlib>  
#include<cmath>  
#include<set>  
#include<list>  
#include<deque>  
#include<map>  
#include<queue>
using namespace std;
 
typedef long long LL;
typedef pair<int,int> P;
//const int xp[]={-1,-1,-1,0,0,1,1,1};
//const int yp[]={-1,0,1,-1,1,-1,0,1};
const int xp[]={-1,0,0,1};
const int yp[]={0,-1,1,0};
const int MAXN=300005;
const int MAXM=2e5+10;
const int INF=1e9;
const LL mod=1e9+7;
const double eps=1e-6;

int n,m,a[100050],b[100050],k[10050],p[10050];
LL dp[20][20035];

int main(){
    ios::sync_with_stdio(false);
    while(cin>>n>>m){
        for(int i=1;i<=n;i++) cin>>a[i]>>b[i];
        for(int i=1;i<=m;i++) cin>>k[i]>>p[i];
        for(int id=0;id<=10;id++){
            memset(dp[id],63,sizeof(dp[id]));
            dp[id][0]=0;
            for(int j=1;j<=1000;j++)
                for(int i=1;i<=m;i++)
                    dp[id][j]=min(dp[id][j],dp[id][max(0,j-(p[i]-id))]+k[i]);
        }
        LL sum=0;
        for(int i=1;i<=n;i++){
            if (dp[b[i]][a[i]]>=4557430888798830399){
                sum=-1; break;
            }
            sum+=dp[b[i]][a[i]];
        }
        cout<<sum<<endl;
    }
    return 0;
}