#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

const int INF = 1e9;

bool solve() {
    int n, m;
    if (scanf("%d%d", &n, &m) != 2) return false;

    vector<vector<int>> monsters(11, vector<int>());
    vector<pii> attacks(m);
    for (int i = 0; i < n; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        monsters[b].push_back(a);
    }
    for (int i = 0; i < m; i++) scanf("%d%d", &attacks[i].first, &attacks[i].second);

    ll ans = 0;
    for (int b = 0; b <= 10; b++) {
        auto& monster = monsters[b];
        if (monster.empty()) continue;
        sort(monster.begin(), monster.end());
        int maxa = monster.end()[-1];
        vector<int> dp(2*maxa+1, INF);
        dp[0] = 0;
        for (const pii attack : attacks) {
            if (attack.second <= b) continue;
            int att = min(maxa, attack.second - b);
            for (int a = att; a <= 2*maxa; a++) {
                dp[a] = min(dp[a], dp[a-att] + attack.first);
            }
        }
        for (int i = 2*maxa-1; i >= 0; i--) dp[i] = min(dp[i], dp[i+1]);

        if (dp[maxa] == INF) {
            ans = -1;
            break;
        }
        
        for (int mon : monster) ans += dp[mon];
    }
    printf("%lld\n", ans);

    return true;
}

int main() {
    while (solve());
    return 0;
}