/in/foo.cc: In function 'int change(long long int)':
/in/foo.cc:21:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:28:4: warning: 'c' may be used uninitialized in this function [-Wmaybe-uninitialized]
   a=c;b=a;c=b;
   ~^~