#include<cstdio>
#include<algorithm>
using namespace std;
const int N=100010,M=1010,inf=~0U>>1;
long long ans;
int n,m,i,j,B,f[M],g[11][M];
struct P{int x,y;}a[N],b[M];
inline void up(int&a,int b){a>b?(a=b):0;}
int main(){
  while(~scanf("%d%d",&n,&m)){
    for(i=0;i<n;i++)scanf("%d%d",&a[i].x,&a[i].y);
    for(i=0;i<m;i++)scanf("%d%d",&b[i].x,&b[i].y);
    for(B=0;B<=10;B++){
      for(i=1;i<=1000;i++)f[i]=inf;
      for(i=0;i<1000;i++)if(f[i]<inf)for(j=0;j<m;j++)if(b[j].y>B)up(f[min(i+b[j].y-B,1000)],f[i]+b[j].x);
      for(i=999;i;i--)up(f[i],f[i+1]);
      for(i=1;i<=1000;i++)g[B][i]=f[i];
    }
    ans=0;
    for(i=0;i<n;i++)if(g[a[i].y][a[i].x]<inf)ans+=g[a[i].y][a[i].x];else{ans=-1;break;}
    printf("%I64d\n",ans);
  }
}