#include<stdio.h>
int a, b, c, d;
int main() {
    int i;
    int answer = 0;
    scanf("%d %d %d %d", &a, &b, &c, &d);
    for(i = 1;i <= a;i++) {
        if((i * c) <= b) {
            if((i + i * c) <= d) {
                answer = i;
            }
        }
    }
    printf("%d\n", answer);
    return (0);
}