#include <bits/stdc++.h>
using namespace std;
#ifdef tabr
#include "library/debug.cpp"
#else
#define debug(...)
#endif

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    while (cin >> n >> m) {
        vector<int> a(n), b(n);
        for (int i = 0; i < n; i++) {
            cin >> a[i] >> b[i];
        }
        vector<int> k(m), p(m);
        for (int i = 0; i < m; i++) {
            cin >> k[i] >> p[i];
        }
        const int inf = (int) 1e9;
        vector<vector<int>> c(11, vector<int>(2501, inf));
        for (int x = 0; x <= 10; x++) {
            c[x][0] = 0;
            for (int i = 0; i < m; i++) {
                if (p[i] <= x) {
                    continue;
                }
                for (int y = 0; y <= 2500 - (p[i] - x); y++) {
                    c[x][y + (p[i] - x)] = min(c[x][y + (p[i] - x)], c[x][y] + k[i]);
                }
            }
            for (int i = 2499; i >= 0; i--) {
                c[x][i] = min(c[x][i], c[x][i + 1]);
            }
        }
        long long ans = 0;
        for (int i = 0; i < n; i++) {
            if (c[b[i]][a[i]] == inf) {
                ans = -1;
                break;
            }
            ans += c[b[i]][a[i]];
        }
        cout << ans << '\n';
    }
    return 0;
}