#include <bits/stdc++.h>
using namespace std;

const int maxn = 1e3 + 10;
typedef long long ll;
const ll inf = 1e16;

int main() {
    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];
        }
        vector<vector<ll>> dp(11, vector<ll>(maxn, inf));        
        for (int j = 0; j <= 10; j++) {
            dp[j][0] = 0;
            for (int i = 0; i < m; i++) {
                if (p[i] < j) continue;
                int v = p[i]-j;
                for (int l = 0; l <= 1000; l++) {
                    dp[j][min(l+v, 1000)] = min(dp[j][min(l+v, 1000)], dp[j][l] + k[i]);
                }
            }
        }
        for (int j = 0; j <= 10; j++) {
            for (int i = 1000; i >= 0; i--) {
                dp[j][i] = min(dp[j][i], dp[j][i+1]);
            }
        }
        
        ll res = 0, flag = true;
        for (int i = 0; i < n; i++) {
            if (dp[b[i]][a[i]] == inf) {
                flag = false; break;
            }
            res += dp[b[i]][a[i]];
        }
        if (flag) {
            cout << res << endl;
        } else {
            cout << -1 << endl;
        }
    }
}