#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));
	if (meat_lim < food_lim){
		if (meat_lim < A){
			printf("%d\n", meat_lim);
		}
		else {
			printf("%d\n", A);
		}
	}
	else{
		printf("%d\n", food_lim);
	}
	return 0;
}