View Compilation Error

0_0_26174820_304.cpp:1:1: error: 'include' does not name a type
 include <stdio.h>
 ^
0_0_26174820_304.cpp: In function 'int main(int, char**)':
0_0_26174820_304.cpp:6:21: error: 'scanf' was not declared in this scope
 while(scanf("%lf",&a)!=EOF)
                     ^
0_0_26174820_304.cpp:6:24: error: 'EOF' was not declared in this scope
 while(scanf("%lf",&a)!=EOF)
                        ^
0_0_26174820_304.cpp:8:19: error: 'printf' was not declared in this scope
 printf("%.3lf\n",b);
                   ^