View Compilation Error

0_0_23578016_1697.cpp: In function 'int isPrime(int)':
0_0_23578016_1697.cpp:5:35: error: 'sqrt' was not declared in this scope
     for (int i = 2; i < sqrt(p*1.0); i ++)
                                   ^
0_0_23578016_1697.cpp: In function 'int main()':
0_0_23578016_1697.cpp:18:11: error: 'cin' was not declared in this scope
     while(cin >> n)
           ^
0_0_23578016_1697.cpp:24:17: error: 'cout' was not declared in this scope
                 cout << i << ' ' << n-i <<endl;
                 ^
0_0_23578016_1697.cpp:24:43: error: 'endl' was not declared in this scope
                 cout << i << ' ' << n-i <<endl;
                                           ^