谜之阶乘（factorial）
You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.
【输入样例 1】
3
1
6
120
【输出样例 1】
-1
2
3 1
6 5
3
5 1
6 3
120 119
You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.
3
1
6
120
-1
2
3 1
6 5
3
5 1
6 3
120 119
