View Compilation Error

0_0_31693858_26536.cpp: In function 'int main()':
0_0_31693858_26536.cpp:5:18: error: 'scanf' was not declared in this scope
     scanf("%d",&c);
                  ^
0_0_31693858_26536.cpp:8:34: error: 'sqrt' was not declared in this scope
         printf("%d\n",(int)sqrt(n));
                                  ^
0_0_31693858_26536.cpp:8:35: error: 'printf' was not declared in this scope
         printf("%d\n",(int)sqrt(n));
                                   ^