题解 | 清楚姐姐买竹鼠
清楚姐姐买竹鼠
https://www.nowcoder.com/practice/816dfe69f83042108cf8c74531a94a35
a,b,x = map(int,input().split())
if x<3 or a*3<b:
print(a*x)
else:
num = x // 3
rem = x % 3
res1 = b*num+rem*a
res2 = b*(num+1)
print(min(res1,res2))
