from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
# input = sys.stdin.readline

A,B,C,D = map(int,input().split())
now = 0
for i in range(1,A+1):
    if(C*i<=B)&((C+1)*i<=D):
        continue
    else:
        print(i-1)
        exit()