a,b,c,d = map(int,input().split())
ans = 0
if a - 1 > 0 and b - c > 0 and d - (1 + c) > 0:
    while a > 0 and b > 0 and d > 0:
        ans += 1
        a -= 1
        b -= c
        d -= (1 + c)
print(ans)