using System;

using System.Collections.Generic;

​

public class T {

static List<int> addLists(int[] l1, int[] l2) {

    var res = new List<int>(Math.Max(l1.Length, l2.Length) + 1);

    int carry = 0;

    int i1 = l1.Length - 1, i2 = l2.Length - 1;

    for(; i1 >= 0 && i2 >= 0; --i1, --i2) {

        int s = l1[i1] + l2[i2] + carry;

        res.Add(s % 10);

        carry = s / 10;

    }

    for(; i1 >= 0; --i1) {

        int s = l1[i1] + carry;

        res.Add(s % 10);

        carry = s / 10;        

    }

    for(; i2 >= 0; --i2) {

        int s = l2[i2] + carry;

        res.Add(s % 10);

        carry = s / 10;        

    }

    if(carry > 0) res.Add(carry);

    res.Reverse();

    return res;

}

​

public static void Main() {

    var r = addLists(new int[]{3,4,9,7,1}, new int[]{4,3});

    foreach(var i in r) Console.Write("{0} ", i);

    Console.WriteLine();

    r = addLists(new int[]{9,9,9,9,9}, new int[]{1});

    foreach(var i in r) Console.Write("{0} ", i);

}

}