#include <stdio.h>
#include <stdlib.h>

int main()
{
        int A, B, C, D;
        scanf("%d%d%d%d", &A, &B, &C, &D);

        int n = D / (1+C);
        if (n > A)
                n = A;
        if (n*C > B)
                n = B / (n*C);
        printf("%d\n", n);
        exit(0);
}