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

const int maxn = 1055;
const int maxm = 100055;

template <class TAT>
void read(TAT &a)
{
    static char ch;
    while ((ch = getchar()) < '0' || ch > '9');
    a = ch - '0';
    while ((ch = getchar()) >= '0' && ch <= '9') a = a * 10 + ch - '0';
}

template <class TAT>
void Ckmin(TAT &a, const TAT &b)
{
    if (a > b) a = b;
}

int n, m;
int cost[maxn], agg[maxn];
int hp[maxm], def[maxm];
int f[11][maxn];

void Pre()
{
    memset(f, 0x3f, sizeof(f));
    for (int base = 0; base <= 10; ++base) {
        f[base][0] = 0;
        for (int i = 0; i <= 1000; ++i) {
            for (int j = 1; j <= m; ++j) {
                if (agg[j] > 0) {
                    if (i + agg[j] <= 1000) {
                        Ckmin(f[base][i + agg[j]], f[base][i] + cost[j]);
                    }
                    else {
                        Ckmin(f[base][1000], f[base][i] + cost[j]);
                    }
                }
            }
        }
        for (int i = 1000; i >= 1; --i) {
            Ckmin(f[base][i - 1], f[base][i]);
        }
        for (int i = 1; i <= m; ++i) {
            --agg[i];
        }
    }
}

void Solve()
{
    long long Ans = 0;
    for (int i = 1; i <= n; ++i) {
        if (def[i] > 10 || f[def[i]][hp[i]] > (1e9+100)) {
            puts("-1");
            return;
        }
        Ans += f[def[i]][hp[i]];
    }
    cout << Ans << endl;
}

int main()
{
    while (scanf("%d%d", &n, &m) != EOF) {
        for (int i = 1; i <= n; ++i) {
            read(hp[i]); read(def[i]);
        }
        for (int i = 1; i <= m; ++i) {
            read(cost[i]); read(agg[i]);
        }
        Pre();
        Solve();
    }
    return 0;
}