can anyone explain this concept and a solution for my problem I can't understand

package com.codegym.task.task05.task0532;
import java.io.*;
/*
Task about algorithms
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
int N = Integer.parseInt(reader.readLine());
int maximum=Integer.MIN_VALUE;
if(N > 0){
for (int i=0; i<N; i++){
int n = Integer.parseInt(reader.readLine());
n+=i;
i++;
System.out.println(n);
}
}
//write your code here
}
}