a = None
b = None
c = None
d = None
x = None
while True:
a = int(input())
b = int(input())
c = int(input())
d = int(input())
x = int(input())
if a == 0:
print(a)
break
elif b == 0:
print(a + b)
break
elif c == 0:
print(a + b + c)
break
elif d == 0:
print(a + b + c + d)
break
elif x == 0:
print( a + b + c + d + x)
break
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