#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<iostream>
#define ll long long
#define inf 1e9
#define eps 1e-10
#define md
#define N 1010
using namespace std;
int a[100010],b[100010];
int c[N],d[N],f[13][N],mx[13];
int main()
{
    int m,n;
    while (scanf("%d%d",&n,&m)!=EOF)
    {
        //memset(mx,0,sizeof(mx));
        for (int i=1;i<=n;i++)
        {
            scanf("%d%d",&a[i],&b[i]);
        ///    mx[b[i]]=max(mx[b[i]],a[i]);
        }
        for (int j=1;j<=m;j++)
            scanf("%d%d",&c[j],&d[j]);
        for (int fen=0;fen<=10;fen++)
        {
            int *g=f[fen];
            for (int i=0;i<=2000;i++) g[i]=inf;
            g[0]=0;
            for (int i=1;i<=m;i++)
            {
                int sz=d[i]-fen;
                if (sz<=0) continue;
                for (int v=sz;v<=2000;v++)
                    g[v]=min(g[v],g[v-sz]+c[i]);
            }
            for (int v=1999;v>=0;v--)
                g[v]=min(g[v],g[v+1]);
        }
        ll ans=0;
        bool ok=1;
        for (int i=1;i<=n;i++)
            if (f[b[i]][a[i]]<inf)
                ans=ans+f[b[i]][a[i]];
            else {ok=0; break;}
        if (ok) cout<<ans<<endl;
        else printf("-1\n");
    }
    return 0;
}