有些题目里要求的输出格式类似如下：
For every test case, you should output 'Case #x: y',where x indicates the case number and counts from 1 and y is the answer required.
或者 'Case #x:'后需换行。
不同题目有不同要求，请格外注意！
例：
#include <cstdio>
using namespace std;
int main() {
    int nCases;
    scanf("%d", &nCases);
    for (int iCase = 1; iCase <= nCases; ++iCase) {
        int a, b;
        scanf("%d%d", &a, &b);
        //printf("Case #%d:\n", iCase);
		//printf("Case #%d: ", iCase);
        printf("%d\n", a+b);
    }
    return 0;
}