Sum 1..N with i++

Use a counter and the ++ operator in a loop to add up every integer from 1 to N.

Input: one integer N.

Output: one line — the sum 1 + 2 + ... + N.

Example 1

Input

Output

1 <= N <= 1000000

Hint 1

The loop's i++ advances the counter each pass.

Hint 2

Use long for the sum since N can be up to a million.

A standard counting loop: i starts at 1 and i++ moves it forward until it passes N, adding each value to the running sum. long is needed because the sum for N = 1000000 exceeds the int range.

Submit an attempt to unlock the solution. (Sign in first.)

Related Problems

Input (stdin)

Output