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

int main(void){
int a,b,c,d;
int eatbaleve,eatableme;
scanf("%d %d %d %d",&a,&b,&c,&d);
for(int i=1;;i++){
    eatbaleve=i;
    eatableme=eatbaleve*c;
    if(eatbaleve>a){break;}
    if(eatableme>b){break;}
    if(eatbaleve+eatableme>d){break;}
}
printf("%d\n",eatbaleve-1);
}