Combinations

package main

import "fmt"

func main() {
    var n, combinations int
    fmt.Scanln(&n)

    for a := 0; a <= n; a++ {
        for b := 0; b <= n; b++ {
            for c := 0; c <= n; c++ {
                if a + b + c == n {
                    combinations++
                }
            }
        }
    }

    fmt.Println(combinations)
}