5.The Simple Problem

Title Description

Solo Went to University , Interested in Mathematics , One day he faced three points , One Sequence( The sequence ) In front of him , It baffled him ……
The sequence is as follows ：S(a,k,n)=a+(k+a)+(2k+a)+…+(nk+a), The title asks him to sum the sequences , however a、k、n There are many values , He doesn't know what to do , So he decided to write a program ……
Can you get it?

Topic data range ：

1. 0<=a<=100.
0<=k<=100.
0<=n<=100.

Answer request time limit ：1000ms, Memory limit ：64MB

Input

There is only one line of input , Contains three integers a、k and n.

Output

According to the input a、k and n, Output S(a,k,n) Value .

Examples

sample input 1  Copy

1 2 4

sample output 1

25

Tips

In the example a=1,k=2,n=4, be S(a,k,n)=1+3+5+7+9=25.

package com;

import java.util.Scanner;

public class Main {
    public static void main(String[] args){
        Scanner s = new Scanner(System.in);
        System.out.println(sum(s.nextInt(),s.nextInt(),s.nextInt()));
    }

    public static int sum(int a,int k,int n){
        int sum = 0;
        for(int i=0;i<=n;i++){
            sum += i*k + a;
        }
        return sum;
    }
}