p, d, m, s = input().strip().split(' ')
p, d, m, s = [int(p), int(d), int(m), int(s)]

gameCount=0
while(s>=0):
    if (p>=m):
        s=s-p
        p=p-d
        gameCount+=1
    else:
        s=s-m
        gameCount+=1

if (s<0):
    print (gameCount-1)
else:
    print (gameCount)