#include <bits/stdc++.h>
using namespace std;
const int N = 1010;
const int M = 110;
int n, m, m1, m2;
int f[N][M][M];

int main() {
    cin >> m1 >> m2 >> n;
    memset(f, 0x3f, sizeof f);
    f[0][0][0] = 0;

    for (int i = 1; i <= n; i++) {
        int v1, v2, w;
        cin >> v1 >> v2 >> w;
        for (int j = 0; j <= m1; j++)
            for (int k = 0; k <= m2; k++) {
                f[i][j][k] = f[i - 1][j][k];
                f[i][j][k] = min(f[i - 1][j][k], f[i - 1][max(0, j - v1)][max(0, k - v2)] + w);
            }
    }
    cout << f[n][m1][m2] << endl;
    return 0;
}