#include <bits/stdc++.h>
using namespace std;
const int MAXN=2010;
const long long INF=1LL<<60;
long long F[MAXN];
int N,M,V[MAXN],C[MAXN];
vector<int> A[11];
int get()
{
    int x;bool f=0;char c;
    while (!isdigit(c=getchar())) if (c=='-') f=1;
    x=c-48;
    while (isdigit(c=getchar())) x=(x<<1)+(x<<3)+c-48;
    if (f) return -x;else return x;
}
long long cal(int b)
{
    for (int i=1;i<=2000;++i) F[i]=INF;
    F[0]=0;
    for (int i=1;i<=M;++i)
        if (V[i]>b)
        {
            int v=V[i]-b;
            for (int j=v;j<=2000;++j) F[j]=min(F[j],F[j-v]+C[i]);
        }
    for (int i=2000-1;i>=0;--i) F[i]=min(F[i],F[i+1]);
    long long Ans=0;
    for (int i=0;i<A[b].size();++i)
        if (F[A[b][i]]==INF)
            return -1;
        else Ans+=F[A[b][i]];
    return Ans;
}
void Solve()
{
    for (int i=0;i<=10;++i) vector<int>().swap(A[i]);
    for (int i=1;i<=N;++i)
    {
        int a,b;
        a=get();b=get();
        A[b].push_back(a);
    }
    for (int i=1;i<=M;++i) C[i]=get(),V[i]=get();
    long long Ans=0;
    for (int i=0;i<=10;++i)
    {
        long long v=cal(i);
        if (v==-1) {printf("-1\n");return ;}
        Ans+=v;
    }
    cout<<Ans<<endl;
}
int main()
{
    while (~scanf("%d%d",&N,&M)) Solve();
    return 0;
}