View Compilation Error

0_0_37986847_27167.cpp: In function 'int main()':
0_0_37986847_27167.cpp:4:12: error: 'cin' was not declared in this scope
     while( cin >> n ) {
            ^
0_0_37986847_27167.cpp:5:41: error: 'scanf' was not declared in this scope
     for(int i=1;i<=n;i++) scanf("%d",a+i);
                                         ^
0_0_37986847_27167.cpp:20:20: error: 'printf' was not declared in this scope
     printf("%d",lcm);
                    ^