View Compilation Error

0_0_28001147_14379.cpp: In function 'int main()':
0_0_28001147_14379.cpp:36:18: error: 'x' was not declared in this scope
   scanf("%I64d",&x);
                  ^
0_0_28001147_14379.cpp:38:13: error: 'a' was not declared in this scope
   for ( ; ; a -- ) if ( check(a) ) break ;
             ^
0_0_28001147_14379.cpp:39:13: error: 'b' was not declared in this scope
   for ( ; ; b ++ ) if ( check(b) ) break ;
             ^
0_0_28001147_14379.cpp:40:26: error: 'a' was not declared in this scope
   LL ans = min( abs( x - a * a ) , abs( b * b - x ) ) ;
                          ^
0_0_28001147_14379.cpp:40:41: error: 'b' was not declared in this scope
   LL ans = min( abs( x - a * a ) , abs( b * b - x ) ) ;
                                         ^