define f(A) = 1, f(a) = -1, f(B) = 2, f(b) = -2, ... f(Z) = 26, f(z) = -26;
输入数据N行， sum=y+f(x)
6
X: Y:
R 1
P 2
G 3
r 1
p 2
g 3
输出
19
18
10
-17
-14
-4

sum=(isupper(x)?(y+x-'A'+1):(y-(x-'a'+1)));