#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include <map>
#include <sstream>
using namespace std;


int n, m;
vector<int> a, b, k, p;

int cache[11][1001];

int calc(int b)
{
    vector<int> np;

    for (int i = 0; i < m; ++i) {
        np.push_back(p[i] - b);
    }

    int M = 100000001;
    for (int i = 1; i <= 1000; ++i) {
        int t = M;

        for (int j = 0; j < np.size(); ++j) if (np[j] > 0) {
            int t1 = k[j];
            if (i > np[j]) {
                t1 += cache[b][i - np[j]];
            }

            if (t1 < t) t = t1;
        }

        cache[b][i] = t;
    }

    for (int i = 1; i <= 1000; ++i) {
        if (cache[b][i] >= M) cache[b][i] = -1;
    }
}

void process()
{
    a.resize(n);
    b.resize(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i] >> b[i];
    }

    k.resize(m);
    p.resize(m);
    for (int i = 0; i < m; ++i) {
        cin >> k[i] >> p[i];
    }

    for (int b = 0; b <= 10; ++b) {
        calc(b);
    }


    long long ans = 0;
    for (int i = 0; i < n; ++i) {
        int t = cache[b[i]][a[i]];
        if (t == -1) {
            cout << -1 << endl;
            return;
        }
        ans += t;
    }

    cout << ans << endl;

    /*
    int n;
    cin >> n;
    vector<int> nums(n);

    string s;
    // NOTE: if using getline() to read the input, the following two lines should be
    // added to read the line sepeartor in the first line. 
    getline(cin, s);

    getline(cin, s);
    stringstream S(s);
    */
}

int main(void)
{
    while (cin >> n >> m) {
        process();
    }
    return 0;
}