#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<utility>
using namespace std;
#define MS(m,z) memset(m,z,sizeof(m))
typedef unsigned U; typedef pair<int,int > P; typedef long long ll;
void inp();
int main(){
#ifdef XS
    freopen("1004.in","r",stdin);
#endif
    while(1)inp();
    return 0;
}
const int J=1e3+10,K=10+5;
int dp[2][J][K];
const int inf=0x7fffffff,N=1e5+10;;
P mon[N];
void inp(){
    int n,m;if(scanf("%d%d",&n,&m)==EOF)exit(0);
    int i,j,k,ki,pi;
    for(i = 0;i<2;i++)for(j =0 ;j<J;j++)for(k=0;k<K;k++)dp[i][j][k]=inf;
    for(i=0;i<2;i++)for(k=0;k<K;k++)dp[i][0][k]=0;
    for(i=0;i<n;i++)scanf("%d%d",&mon[i].first,&mon[i].second);
    int tmp,f;
    for(i=1;i<=m;i++){
        scanf("%d%d",&ki,&pi);
        f=i&1;
        for(j=1;j<=1000;j++){
            for(k=0;k<=10;k++){
                if(k>=pi){
                    dp[f][j][k]=dp[!f][j][k];
                }
                else {
                    tmp = j-(pi-k);
                    if(tmp<0)tmp=0;
                    dp[f][j][k]=min(dp[f][tmp][k]+ki,dp[!f][j][k]);
                }
            }
        }
    }
    int a,b;
    ll ans=0;
    for(i = 0;i<n;i++){
        a=mon[i].first,b=mon[i].second;
#ifdef XS
        printf("dp[%d][%d] = %d\n",a,b,dp[f][a][b]);
#endif
        if(dp[f][a][b]==inf){
            puts("-1");
            return ;
        }
        ans+=dp[f][a][b];
    }
    printf("%I64d\n",ans);
}
//1004.cc by xsthunder at Sat Aug  5 14:44:10 2017