View Compilation Error

0_0_33895456_9301.c:3:1: error: unknown type name 'using'
 using namespace std;
 ^
0_0_33895456_9301.c:3:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
 using namespace std;
                 ^
0_0_33895456_9301.c: In function 'main':
0_0_33895456_9301.c:15:8: error: 'cin' undeclared (first use in this function)
  while(cin>>n>>a>>b)
        ^
0_0_33895456_9301.c:15:8: note: each undeclared identifier is reported only once for each function it appears in
0_0_33895456_9301.c:17:11: error: 'cout' undeclared (first use in this function)
  if(n==1) cout<<a;
           ^
0_0_33895456_9301.c:43:10: error: 'endl' undeclared (first use in this function)
    cout<<endl;
          ^