参考：https://blog.csdn.net/u010885899/article/details/46636523
http://kqwd.blog.163.com/blog/static/4122344820091041127552/
https://blog.csdn.net/nanchengbian/article/details/9077869
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 using namespace std; 5 int main() 6 { 7 int n; 8 while (cin>>n&&n) 9 { 10 if (n&1)//判断奇数 11 { 12 cout<<n-1<<endl; 13 } 14 else 15 { 16 cout<<"No Solution!"<<endl; 17 } 18 } 19 20 return 0; 21 }