/in/foo.cc: In function 'int main()':
/in/foo.cc:10:17: error: 'x' was not declared in this scope
   10 |                 x=x*10+s%10;
      |                 ^
/in/foo.cc:13:12: error: 'x' was not declared in this scope
   13 |         if(x==n)
      |            ^
/in/foo.cc:5:17: warning: unused variable 'z' [-Wunused-variable]
    5 |         int n,s,z=0;
      |                 ^