c++ prac prog - 15

#include <iostream.h>
#include <conio.h>

void main()
{
    clrscr();
    unsigned int n,sum(0);
    cout << "Enter a number: ";
    cin >> n;
    for (int i(1); i<=n; i++)
        sum+=i;
    cout << "\n\nSum of nos. from 1 to " << n << " is " << sum << endl;
    getch();
}