#include "bits/stdc++.h"
#define in std::cin
#define out std::cout
#define rep(i,N) for(LL i=0;i<N;++i)
typedef long long int LL;

int main()
{
	LL A, B, C, D;
	in >> A >> B >> C >> D;

	LL ans = std::min(B / C, A);
	ans = std::min(ans, D / 4);
	out << ans << std::endl;
}