#include <cstdio>
#include <cmath>

int main( void ){
	int A,B,C,D;
	if(!scanf( "%d%d%d%d", &A, &B, &C, &D ))
		return -1;
	int meat_lim = (int)(B/C);
	int food_lim = (int)(D/(1+C));
	int min = meat_lim;
	if (min > A)
		min = A;
	if (min > food_lim)
		min = food_lim;
	printf("%d\n", min);
	return 0;
}