#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
long long maxf= 0;
struct magic{
    int att;
    int cos;
}mas[1005];
int n,m;
struct mob{
    int hp;
    int def;
}mos[100005];
inline long long min(long long a,long long b){
    return a>b?b:a;
}
long long  dp[12][2333];
void ouput(){
    for(int i=0;i<11;i++){
        for(int j=0;j<1000;j++){
                printf("%d ",dp[i][j]);
        }
        putchar('\n');
        } 
}

int main(void){
    while(~scanf("%d%d",&n,&m)){
        memset(dp,0x7f,sizeof(dp));  
        maxf = dp[0][0];
        for(int i=0;i<n;i++)
            scanf("%d %d",&mos[i].hp,&mos[i].def);
        for(int i=0;i<m;i++) 
            scanf("%d %d",&mas[i].cos,&mas[i].att);
        for(int i=0;i<12;i++){
            dp[i][0]=0;
            for(int j=0;j<m;j++){
                if(mas[j].att-i<=0) continue ; 
                for(int k=0;k<2333;k++){
                    if(k<mas[j].att-i){
                        dp[i][k] = min(dp[i][k],mas[j].cos);
                    }else{
                        dp[i][k] = min(dp[i][k],dp[i][k-mas[j].att+i]+mas[j].cos);
                    }
                }
            
            }
            for(int j=2332;j>=0;j--){
                 dp[i][j]=min(dp[i][j],dp[i][j+1]);  
            }   
        }
        int i=0;
        long long sum = 0;

        for(i=0;i<n;i++){
            if(dp[mos[i].def][mos[i].hp]>=maxf){
                break;
            }else{
                sum+= dp[mos[i].def][mos[i].hp];
            }
        }
        if(i==n)
        printf("%I64d\n",sum);
        else
        printf("-1\n",sum);
    }
}