View Compilation Error

0_0_38544430_24472.cpp:1:1: error: 'include' does not name a type
 include<iostream>
 ^
0_0_38544430_24472.cpp: In function 'int main()':
0_0_38544430_24472.cpp:8:1: error: 'cout' was not declared in this scope
 cout<<"十进制:";
 ^
0_0_38544430_24472.cpp:9:1: error: 'cin' was not declared in this scope
 cin>>num;
 ^
0_0_38544430_24472.cpp:10:7: error: 'numn' was not declared in this scope
 while(numn/2)
       ^