#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define F first
#define S second
#define MASK(i) (1 << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define f(i, l, r) for(int i = l; i <= r; ++i)
const int mod = 1e9 + 7;
const int ars = 2e5 + 5;
const ll infll = 1e18;
int s, n, v[ars], w[ars], k[ars];
void sub1(){
cout << min(v[1] * k[1], v[1] * s / w[1]);
}
signed main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> s >> n;
f(i, 1, n){
cin >> v[i] >> w[i] >> k[i];
}
if(n == 1) sub1();
return 0;
}
