foo.cpp:1:1: error: 'include' does not name a type
 include<iostream> include<cstring> include<cstdio> include<cmath>
 ^~~~~~~
foo.cpp: In function 'int main()':
foo.cpp:6:14: error: 'scanf' was not declared in this scope
 scanf("%d",&n);
              ^
foo.cpp:14:1: error: 'cout' was not declared in this scope
 cout<<f[n];
 ^~~~