#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <set>
#include <vector>
#include <utility>
#include <stack>
#include <deque>
#include <queue>
#include <string>
#include <cctype>
#include <ctime>
#include <sstream>
#include <map>
//#define LOCAL
#define ll long long
#define maxn 100005
#define maxm 4000
#define maxv 4000
#define INF 100000000
using namespace std;

int n, m; ll V;
ll k[maxm], p[maxm];
ll d[maxv][12];

void dp(int define)
{
    for(int v = 1; v <= V; v++) d[v][define] = INF;
    d[0][define] = 0; int failed = 1;
    for(int i = 0; i < m; i++)
    {
        if(p[i] <= define) continue;
        failed = 0;
        for(int v = p[i]-define; v <= V; v++)
        {
            if(d[v-(p[i]-define)][define] != INF)
                d[v][define] = min(d[v][define], d[v-(p[i]-define)][define] + k[i]);
        }
    }
    if(failed)
    {
        for(int i = 0; i <= V; i++)
            d[i][define] = -1;
    }
    else
    {
        for(int i = V-1; i >= 0; i--)
            d[i][define] = min(d[i][define], d[i+1][define]);
    }
}

ll a[maxn], b[maxn];

int main()
{
#ifdef LOCAL
    freopen("data.in.txt", "r", stdin);
    freopen("data.out.txt", "w", stdout);
#endif
    while(scanf("%d%d", &n, &m) == 2 && n)
    {
        V = 0; ll maxb = 0;
        for(int i = 0; i < n; i++)
            scanf("%lld%lld", &a[i], &b[i]), V = max(V, a[i]), maxb = max(maxb, b[i]);
        for(int i = 0; i < m; i++)
            scanf("%lld%lld", &k[i], &p[i]), V = max(V, p[i]);
        V *= 2;
        for(int i = 0; i <= maxb; i++)
            dp(i);
        ll ans = 0;
        for(int i = 0; i < n; i++)
        {
            if(d[a[i]][b[i]] == -1)
            { ans = -1; break; }
            ans += d[a[i]][b[i]];
        }
        printf("%lld\n", ans);
    }
    return 0;
}