#include<map>    
#include<stack>    
#include<queue>    
#include<vector>    
#include<math.h>    
#include<stdio.h>    
#include<iostream>    
#include<string.h>    
#include<stdlib.h>    
#include<algorithm>    
using namespace std;    
typedef long long  ll;    
#define inf 100000000000000000    
#define mod 1000000007     
#define  maxn  1000010    
#define  lowbit(x) (x&-x)    
#define  eps 1e-10   
ll a[maxn],b[maxn],dp[2006][15],k[maxn],p[maxn];
int  main(void)
{
    ll n,m,i,j,ans,m1,m2,maxs;
    while(scanf("%lld%lld",&n,&m)!=EOF)
    {
        ans=0;m1=m2=0;maxs=0;
        for(i=1;i<=n;i++)
        {
            scanf("%lld%lld",&a[i],&b[i]);
            m1=max(m1,b[i]);
            maxs=max(maxs,a[i]);
        }
        for(i=1;i<=m;i++)
        {
            scanf("%lld%lld",&k[i],&p[i]);
            m2=max(m2,p[i]);
        }
        if(m1>=m2)
        {
            printf("-1\n");
            continue;
        }
        for(i=1;i<=2005;i++)
            for(j=0;j<=10;j++)
                dp[i][j]=inf;
        for(i=0;i<=10;i++)  
        {  
            dp[0][i]=0;  
            for(j=1;j<=m;j++)  
            {  
                ll t=p[j]-i;
                if(t<=0) 
                    continue;  
                for(ll h=t;h<=2003;h++)  
                    dp[h][i]=min(dp[h-t][i]+k[j],dp[h][i]);  
            }  
            for(j=2002;j>=0;j--)   
                dp[j][i]=min(dp[j][i],dp[j+1][i]);    
        }  
        for(i=1;i<=n;i++)
            ans+=dp[a[i]][b[i]];
        printf("%lld\n",ans);
    }
    return 0;
}