error C2065: cout: необъявленный идентификатор

void show_big_and_little (int a, int b, int c)

{
int small = a;
int big = a;

if (b > big)
big = b;

if (b < small)
small = b;

if (c > big)
big = c;

if (c < small)
small = c;

cout << "SAMOE BOLHIE ZNAHENIE RAVNO" << big<< endl;
cout << "SAMOE MALENKOE ZNAHENIE RAVNO" << small << endl;
}

void main (void)

{
show_big_and_little (1, 2, 3);
show_big_and_little (500, 0, -500);
show_big_and_little (1001, 1001, 1001);
}