View Compilation Error

0_0_39672672_10139.cpp: In function 'int main()':
0_0_39672672_10139.cpp:11:35: error: 'ceil' was not declared in this scope
   11 |                                 n=ceil((n*1.0)/9);
      |                                   ^~~~
0_0_39672672_10139.cpp:13:35: error: 'ceil' was not declared in this scope
   13 |                                 n=ceil((n*1.0)/2);
      |                                   ^~~~