（python-codefoces）Codeforces Round #540 (Div. 3) A. Water Buying

https://codeforces.com/contest/1118/problem/A

python代码：

import math
q=int(input())
for i in range(q):
    n,a,b=map(int,input().split())
    z=(math.floor(n/2)*min(2*a,b)+(n%2)*a)
    print(z)