#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
struct kk
{
    int a,b;
}x[100010];
bool cmp(kk A,kk B)
{
    return A.b<B.b;
}
int n,m,now,bb,i,j,p[1010];
long long f[2][2010],k[1010];
int main()
{
   while (~scanf("%d%d",&n,&m))
   {
       for (i=1;i<=n;i++) scanf("%d%d",&x[i].a,&x[i].b);
       sort(x+1,x+n+1,cmp);
       for (i=1;i<=m;i++) scanf("%l64d%d",&k[i],&p[i]);
       bool flag=0;
       for (i=1;i<=m;i++) if (p[i]>x[n].b) flag=1;
       if (flag==0)
       {
           printf("-1\n");
           continue;
    } 
       now=1;long long ans=0;
       for (bb=0;bb<=10;bb++)
       {
           if (now>n) break;
           memset(f,70,sizeof(f));
           //f[i][j]: first i,get >=j ,minimum cost
           //all bag
           f[0][0]=f[1][0]=0;
           for (i=1;i<=m;i++)
           {
             int t=i&1;
             for (j=1;j<=2000;j++)
             {
                 f[t][j]=f[(i-1)&1][j];
                 if (p[i]<=bb) continue;
            if (p[i]-bb<=j) f[t][j]=min(f[t][j],f[t][j-p[i]+bb]+k[i]);    
          }
          for (j=2000;j>=1;j--) 
            if (f[t][j]<f[t][j-1])
              f[t][j-1]=f[t][j];
        }
        while (now<=n&&x[now].b==bb)
        {
            ans+=f[m&1][x[now].a];
            now++;
        }
    }
    printf("%I64d\n",ans);
   }    
}