int main()
{
int a, b, c;
b=0;
c=0;
do
{
cout << "Please enter a positive integer (negative integer to stop):"<< ' ';
cin>> a;
if (a%2 == 0)
{
c++;
}
else
b++;
}
while (a>=0);
cout << "You have entered" << ' '<< b << ' ' <<"odd numbers." << endl;
cout << "And" << ' ' << c << ' ' <<"even numbers." << endl;
system("PAUSE");
return 0;
}

int main()
{
int input, even=0, odd=0;
do
{
cout << "Please enter a positive integer (negative integer to stop):"<< ' ';
cin>> input;
if ( (even%2 == 0) && (input >= 0) )
  even++;
else if (input >= 0)
  odd++;
}
while (input>=0);
 
cout << "You have entered" << ' '<< odd << ' ' <<"odd numbers." << endl;
cout << "And" << ' ' << even << ' ' <<"even numbers." << endl;
system("PAUSE");
return 0;
}