#include <stdio.h>

int main(void){
    int a,b,c,d;
    int xxx;
    int ans;
    scanf("%d%d%d%d",&a,&b,&c,&d);
    xxx = b/c;
    if(xxx>a){
        xxx=a;
    }
    while(xxx*(c+1) > d){
            xxx--;
    }
    printf("%d",xxx);
}