View Compilation Error

0_0_18584403_16753.c:3:1: error: unknown type name 'using'
 using namespace std;
 ^
0_0_18584403_16753.c:3:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
 using namespace std;
                 ^
0_0_18584403_16753.c: In function 'main':
0_0_18584403_16753.c:7:26: error: expected expression before '=' token
  while(scanf("%lf",&x))! = EOF;
                          ^