백준 1049번 C++

#include <iostream>
#include <algorithm>

using namespace std;
int n, m;
int minp = 1001;
int mino = 1001;

int main(void) {
	cin >> n >> m;
	int flag = 1;

	if (n % 6 == 0)
		flag = 0;
	for (int i = 0; i < m; i++) {
		int x, y;
		cin >> x >> y;
		minp = min(minp, x);
		mino = min(mino, y);
	}
	int answer = 987654321;
	for (int i = 0; i * 6 <= n; i++) {
		answer = min(answer, minp * i + mino * (n - i*6));
	}
	answer = min(answer, (n / 6 + flag) * minp);
	cout << answer << endl;
	return 0;
}