#include <iostream>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <string>
#include <bitset>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
#include <sstream>
#include <stack>
#include <iomanip>
using namespace std;
#define pb push_back
#define mp make_pair
typedef pair<int,int> pii;
typedef long long ll;
typedef double ld;
typedef vector<int> vi;
#define fi first
#define se second
#define fe first
#define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);}
#define Edg int M=0,fst[SZ],vb[SZ],nxt[SZ];void ad_de(int a,int b){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;}void adde(int a,int b){ad_de(a,b);ad_de(b,a);}
#define Edgc int M=0,fst[SZ],vb[SZ],nxt[SZ],vc[SZ];void ad_de(int a,int b,int c){++M;nxt[M]=fst[a];fst[a]=M;vb[M]=b;vc[M]=c;}void adde(int a,int b,int c){ad_de(a,b,c);ad_de(b,a,c);}
#define es(x,e) (int e=fst[x];e;e=nxt[e])
#define esb(x,e,b) (int e=fst[x],b=vb[e];e;e=nxt[e],b=vb[e])
#define VIZ {printf("digraph G{\n"); for(int i=1;i<=n;i++) for es(i,e) printf("%d->%d;\n",i,vb[e]); puts("}");}
#define VIZ2 {printf("graph G{\n"); for(int i=1;i<=n;i++) for es(i,e) if(vb[e]>=i)printf("%d--%d;\n",i,vb[e]); puts("}");}
#define SZ 666666
ll mc[11][23333];
int n,m,a[SZ],b[SZ],k[SZ],p[SZ];
void work(int s)
{
    ll*c=::mc[s];
    memset(c,127/3,sizeof mc[0]); c[0]=0;
    for(int i=0;i<=1000;++i)
    {
        for(int r=1;r<=m;++r)
        {
            int j=max(p[r]-s,0);
            c[i+j]=min(c[i+j],c[i]+k[r]);
        }
    }
    for(int i=2000;i>=1;--i)
        c[i]=min(c[i],c[i+1]);
}
int main()
{
    if(scanf("%d%d",&n,&m)==EOF) return 0;
    for(int i=1;i<=n;++i) scanf("%d%d",a+i,b+i);
    for(int i=1;i<=m;++i) scanf("%d%d",k+i,p+i);
    for(int i=0;i<=10;++i) work(i);
    ll as=0;
    for(int i=1;i<=n;++i)
    {
        as+=mc[b[i]][a[i]];
        if(as>=1e16) break;
    }
    if(as>=1e16) puts("-1"); else printf("%I64d\n",as);
    main();
}