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

constexpr int inf = 0x3f3f3f3f;
using ll = long long;
int a[100010], b[100010];
int k[100010], p[100010];
int n, m;
ll dp[1010][11];
bool vis[1010][11];

ll gao(int a, int b) {
    if (a <= 0) return 0;
    if (vis[a][b]) return dp[a][b];

    vis[a][b] = true;
    ll &ans = dp[a][b];
    ans = inf;
    for (int i = 0; i < m; ++ i) if (p[i] > 0) {
        ans = min(ans, gao(a - p[i], b) + k[i]);
    }

    return ans;
}

int main(void) {
    ios::sync_with_stdio(false);
    while (cin >> n >> m) {
        for (int i = 0; i < n; ++ i) {
            cin >> a[i] >> b[i];
        }
        for (int i = 0; i < m; ++ i) {
            cin >> k[i] >> p[i];
        }

        memset(vis, false, sizeof(vis));
        memset(dp, -1, sizeof(dp));
        for (int i = 0; i <= 10; ++ i) {
            for (int j = 0; j < m; ++ j) p[j] -= i;
            for (int j = 1; j <= 1000; ++ j) if (!vis[j][i]){
                dp[j][i] = gao(j, i);
            }
            for (int j = 0; j < m; ++ j) p[j] += i;
        }

        ll ans = 0;
        for (int i = 0; i < n; ++ i) {
            if (dp[a[i]][b[i]] >= inf) {
                ans = -1;
                break;
            }
            ans += dp[a[i]][b[i]];
        }
        cout << ans << endl;
    }

    return 0;
}