#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<set>
#include<ctime>
#include<vector>
#include<cmath>
#include<algorithm>
using namespace std;
inline void write(int a){
    if(a>=10)write(a/10);
    putchar('0'+a%10);
}
inline void writeln(int a){
    write(a); puts("");
}
inline int read()//不管是正负数，都可以 
{
    int x = 0; char ch = getchar(); bool positive = 1;
    for (; !isdigit(ch); ch = getchar())    if (ch == '-')    positive = 0;
    for (; isdigit(ch); ch = getchar())    x = x * 10 + ch - '0';
        return positive ? x : -x;
}
const int N=100005;
int T,n,m,a[N],b[N],k[N],p[N],dp[15][2005],oo=1000000005;
long long ans;
int main(){
    while(scanf("%d%d",&n,&m)==2){int flag=ans=0;
        for(int i=1;i<=n;i++){a[i]=read(); b[i]=read();} for(int i=1;i<=m;i++){k[i]=read(); p[i]=read();}
        for(int i=0;i<=10;i++){for(int j=0;j<=2000;j++)dp[i][j]=oo; dp[i][0]=0;}
        for(int i=0;i<=10;i++)
            for(int l=1;l<=m;l++)if(p[l]>i)
                for(int j=p[l]-i;j<=2000;j++){
                    dp[i][j]=min(dp[i][j],dp[i][j-p[l]+i]+k[l]);
                }
        for(int i=0;i<=10;i++){
            for(int j=1999;j;j--){
                dp[i][j]=min(dp[i][j],dp[i][j+1]);
            }
        }
        for(int i=1;i<=n;i++){
            if(dp[b[i]][a[i]]>=oo){flag=1; puts("-1"); break;}ans+=dp[b[i]][a[i]];
        }
        if(!flag)
        cout<<ans<<endl;
    }
}