#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>

using namespace std;
typedef long long LL;
const int maxn  = 1e5+2333;
const int MOD   = 1e9+7;
const LL inf   = 1e18+7;
const double eps= 1e-8;
const double pi = acos(-1.0);
int n,m,tot,cnt,ans,tmp;
inline LL read()
{
    int  c=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        c=c*10+ch-'0';
        ch=getchar();
    }
    return c*f;
}
struct node1
{
    LL a,b,sum;
} king[maxn];
struct node2
{
    LL k,p;
} dd[maxn];
LL dp[2005][15];///dp[i][j]为花费 i为生命值 j为防御值
int main()
{
   // freopen("in.txt","r",stdin);
    while(~scanf("%d %d",&n,&m))
    {
        int monster_sum=0;
        for(int i=1; i<=n; ++i)
        {
            king[i].a=read();
            king[i].b=read();
        }
        for(int i=1; i<=m; ++i)
        {
            dd[i].k=read();
            dd[i].p=read();
        }
        //init inf
        for(int i=0; i<2005; ++i)
            for(int j=0; j<=10; ++j)
                dp[i][j]=inf;

        for(int i=0; i<=10; ++i)
        {
            dp[0][i]=0;
            for(int j=1; j<=m; ++j)
            {
                // LL t=dd[j].p-i;
                LL t=dd[j].p-i;
                if(t<=0) continue;
                for(int pp=t; pp<=2004; ++pp)
                {
                    dp[pp][i]=min(dp[pp-t][i]+dd[j].k,dp[pp][i]);
                }
            }
          for(int j=2003; j>=0; --j)//!!!
            {
               dp[j][i]=min(dp[j][i],dp[j+1][i]);
           }
        }
        int p1=0,p2=0;
        bool flag=false;
        LL ret=0;
        for(int i=1; i<=n; ++i)
            ret+=dp[king[i].a][king[i].b];
        if(ret>=inf) puts("-1");
        else  printf("%I64d\n",ret);
    }
    return 0;
}