#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <iomanip>
#include <cmath>
#include <map>
using namespace std;

const int maxn = 101000;
const int maxm = 1010;

int n, m;
int a[maxn] = {0}, b[maxn] = {0};
long long f[maxm * 2][20] = {0};
long long v[maxm] = {0}, w[maxm] = {0};

void calc() {
    for (int i = 0; i <= 2000; ++i) {
        for (int j = 0; j <= 10; ++j) {
            f[i][j] = (long long)1e10;
        }
    }
    for (int d = 0; d <= 10; ++d) {
        f[0][d] = 0;
        for (int i = 1; i <= m; ++i) {
            if (w[i] <= d) continue;
            for (int j = 0; j <= 2000; ++j) {
                if (j >= w[i] - d) {
                    f[j][d] = min(f[j][d], f[j - w[i] + d][d] + v[i]);
                }
            }
        }
    }
    for (int d = 0; d <= 10; ++d) {
        for (int j = 1999; j >= 0; --j) {
            f[j][d] = min(f[j][d], f[j + 1][d]);
        }
    }
}

int main() {
    ios::sync_with_stdio(0);
    while (cin >> n >> m) {
        for (int i = 1; i <= n; ++i) {
            cin >> a[i] >> b[i];
        }
        for (int i = 1; i <= m; ++i) {
            cin >> v[i] >> w[i];
        }
        calc();
        long long ans = 0;
        for (int i = 1; i <= n; ++i) {
            if (f[a[i]][b[i]] == (long long)1e10) {
                ans = -1;
                break;
            }
            ans += (long long)f[a[i]][b[i]];
        }
        cout << ans << endl;
    }
    return 0;
}