/in/foo.cc: In function 'int main()':
/in/foo.cc:80:17: warning: 'prod' may be used uninitialized in this function [-Wmaybe-uninitialized]
             prod*=Pow((N-1)/2);
             ~~~~^~~~~~~~~~~~~~
/in/foo.cc:53:25: warning: 'v' may be used uninitialized in this function [-Wmaybe-uninitialized]
             int prod=a[v];
                         ^
/in/foo.cc:54:25: warning: 'u' may be used uninitialized in this function [-Wmaybe-uninitialized]
             int prox=a[u];
                         ^