View Compilation Error

0_0_27127485_21718.cpp:1:9: error: #include expects "FILENAME" or <FILENAME>
 #include
         ^
0_0_27127485_21718.cpp: In function 'int main()':
0_0_27127485_21718.cpp:5:22: error: 'scanf' was not declared in this scope
 while(scanf("%lf", &a)!=EOF)
                      ^
0_0_27127485_21718.cpp:5:25: error: 'EOF' was not declared in this scope
 while(scanf("%lf", &a)!=EOF)
                         ^
0_0_27127485_21718.cpp:7:24: error: 'fabs' was not declared in this scope
 printf("%.2lf/n",fabs(a));
                        ^
0_0_27127485_21718.cpp:7:25: error: 'printf' was not declared in this scope
 printf("%.2lf/n",fabs(a));
                         ^