A, B, C, D = map(int, input().split())

if A < 0 or A > 100:
    print("error")
elif B < 0 or B > 100:
    print("error")
elif C <= 0 or C > 100:
    print("error")
elif D < 0 or D > 100:
    print("error")
else:
    condition_1 = min(A, B // C)
    condition_2 = min(condition_1, D // (C + 1))
    print(condition_2)