View Compilation Error

0_0_21205960_9890.cpp: In function 'int main()':
0_0_21205960_9890.cpp:62:10: error: 'cin' was not declared in this scope
    while(cin>>n){
          ^
0_0_21205960_9890.cpp:73:8: error: 'cout' was not declared in this scope
        cout<<prime()<<endl;
        ^