#include<bits/stdc++.h>
using namespace std;
#define ll long long 
#define MAX 100005
#define Max 1005
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while (ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
    while (ch>='0'&&ch<='9'){x=x*10+ch-48;ch=getchar();}
    return x*f;
}
int n,m;
int a[MAX],b[MAX],k[Max],p[Max],dp[15][1005];
ll ans;
int main(){
    
    while(scanf("%d%d",&n,&m)!=EOF){
        ans=0;
        memset(dp,-1,sizeof(dp));
        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++) dp[i][0]=0;
        for(int i=0;i<=10;i++){
            for(int j=1;j<=1000;j++){
                for(int w=1;w<=m;w++){
                    int h=p[w]-i;
                    if(h<=0) continue;
                    if(h>=j){
                        if(k[w]<dp[i][j]||dp[i][j]==-1) dp[i][j]=k[w];
                    }else{
                        if(k[w]+dp[i][j-h]<dp[i][j]||dp[i][j]==-1) dp[i][j]=k[w]+dp[i][j-h];
                    }
                }
            }
        }
        for(int i=0;i<=n;i++){
            if(dp[b[i]][a[i]]==-1){ans=-1;break;}
            ans+=dp[b[i]][a[i]];
        }
        printf("%lld\n",ans);
    }
    
    
    return 0;
}