foo.cc: In function 'int main()':
foo.cc:7:11: error: expected ';' before numeric constant
  cin>>x;3 23 2 
           ^~
foo.cc:18:2: warning: statement has no effect [-Wunused-value]
  }
  ^
foo.cc:6:7: warning: unused variable 'x1' [-Wunused-variable]
  int  x1, x;
       ^~