#include <bits/stdc++.h>
#define Maxn 100007
#define Maxm 1007
#define inf 1000000007
using namespace std;
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-'0';ch=getchar();}
    return x*f;
}
int n,m;
int a[Maxn],b[Maxn];
int k[Maxm],p[Maxm];
int f[1007][15];
int main()
{
    while (scanf("%d%d",&n,&m)==2)
    {
        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 r=0;r<=10;r++)
        {
            for (int i=1;i<=1000;i++)
                f[i][r]=inf;
            f[0][r]=0;
            for (int i=1;i<=1000;i++)
                for (int j=1;j<=m;j++)
                    f[i][r]=min(f[i][r],f[max(0,i-max(0,p[j]-r))][r]+k[j]);
        }
        long long ans=0;
        bool check=true;
        for (int i=1;i<=n;i++)
            if (f[a[i]][b[i]]>=inf) check=false; else ans+=f[a[i]][b[i]];
        if (!check) printf("%d\n",-1); else printf("%lld\n",ans);
    }
    return 0;
}