View Compilation Error

0_0_23327818_418.cpp: In function 'int main()':
0_0_23327818_418.cpp:12:7: error: 'k' was not declared in this scope
    if(k%2==0)
       ^
0_0_23327818_418.cpp:14:19: error: 'ceil' was not declared in this scope
     n=ceil(n*1.0/9);
                   ^
0_0_23327818_418.cpp:17:19: error: 'ceil' was not declared in this scope
     n=ceil(n*1.0/2);
                   ^
0_0_23327818_418.cpp:19:6: error: 'k' was not declared in this scope
   if(k%2==0)
      ^