View Compilation Error

0_0_28693778_29441.c: In function 'main':
0_0_28693778_29441.c:16:39: error: 'cout' undeclared (first use in this function)
                                       cout<<c+29+30*4+31*6<<endl;
                                       ^
0_0_28693778_29441.c:16:39: note: each undeclared identifier is reported only once for each function it appears in
0_0_28693778_29441.c:16:61: error: 'endl' undeclared (first use in this function)
                                       cout<<c+29+30*4+31*6<<endl;
                                                             ^