masi = []
for i in range(1000):
a = int(input())
if a == 0:
break
if a % 3 == 0:
masi.append(a)
print(min(masi))
школа 1747
masi = []
for i in range(1000):
a = int(input())
if a == 0:
break
if a % 3 == 0:
masi.append(a)
print(min(masi))