View Compilation Error

0_0_28282660_21462.cpp: In function 'int main()':
0_0_28282660_21462.cpp:5:22: error: 'scanf' was not declared in this scope
  while(scanf("%lf",&x)!=EOF)
                      ^
0_0_28282660_21462.cpp:5:25: error: 'EOF' was not declared in this scope
  while(scanf("%lf",&x)!=EOF)
                         ^
0_0_28282660_21462.cpp:7:26: error: 'printf' was not declared in this scope
   printf("%.2lf\n",abs(x));
                          ^