#include<bits/stdc++.h>
using namespace std;
const long long INF = 1e17+10;;
int n,m;
int a[100000+10];
int b[100000+10];
long long dp[20][2001];
int k[1005];
int p[1005];

int solve(int kk){
    dp[kk][0]=0;
    for(int i=1;i<=m;i++){
        if(p[i]<=kk)
            continue;
        for(int j = p[i]-kk;j<=2000;j++){
            dp[kk][j] = min(dp[kk][j-p[i]+kk]+(long long)k[i],dp[kk][j]);
        }
    }
    for(int i=1999;i>=1;i--)
        dp[kk][i]=min(dp[kk][i],dp[kk][i+1]);
    return 0;
}

int main(){
    while(~scanf("%d%d",&n,&m)){
    for(int i=1;i<=n;i++)
        scanf("%d%d",&a[i],&b[i]);
    for(int i=1;i<=m;i++)
        scanf("%d%d",&k[i],&p[i]);
    memset(dp,INF,sizeof(dp));
    for(int i=0;i<=10;i++){
        solve(i);
    }
    long long ans = 0;
    bool flag = true;
    for(int i=1;i<=n;i++){
            long long minn = INF;
        for(int j=b[i];j<=10;j++){
            minn = min(minn,dp[j][a[i]]);
        }
        if(minn==INF){
            flag=false;
            break;
        }
       // printf("%d\n",minn);
        ans+=minn;
    }
    if(flag)
        printf("%lld\n",ans);
    else
        printf("-1\n");
    }
    return 0;
}