/in/foo.cc: In function 'int main()':
/in/foo.cc:8:10: warning: right operand of comma operator has no effect [-Wunused-value]
  cin>>n,x;
          ^
/in/foo.cc:9:3: warning: 'x' is used uninitialized in this function [-Wuninitialized]
  a=n%x;
  ~^~~~