/in/foo.cc: In function 'long long int f(long long int, long long int, long long int)':
/in/foo.cc:7:14: error: expected ',' or ';' before '/' token
  LL mid (l+r)/2 , pf = mid * mid;
              ^
/in/foo.cc:8:10: error: 'pf' was not declared in this scope
  if (x < pf) return f(x,l,mid-1);
          ^~
/in/foo.cc:8:10: note: suggested alternative: 'f'
  if (x < pf) return f(x,l,mid-1);
          ^~
          f
/in/foo.cc:9:10: error: 'pf' was not declared in this scope
  if (x < pf + 2 * mid + 1) return mid;
          ^~
/in/foo.cc:9:10: note: suggested alternative: 'f'
  if (x < pf + 2 * mid + 1) return mid;
          ^~
          f