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```import java.util.*;

public class Main {
static int[] calSum(int a[], int b[], int n, int m) {

// array is representing digits of the number and digit can be between 0 to 9
// Initially we took the bigger size as the final size
int size = 0;
int index = 0;
if(n>m)
{
size = n;
index = n-1;
}
else
{
size = m;
index = m-1;
}

int result[] = new int[size];

// We are given two arrays and we need to add these two arrays

// i will point to last element of a (First array)
// j will point to last element of b (Second array)

// right to left
// i will decrease by 1
// j will decrease by 1

// while loop we use in Two pointer

// We are starting from last index
int i = n-1;
int j = m-1;

int carry = 0;

// a = [9, 9, 9, 9], n = 4
// b = [9, 9], m = 2

// STEP 1, i = 3, j = 1, index = 3, sum = 9 + 9 + 0 = 18, for next step carry = 1
// STEP 2, i = 2, j = 0, index = 2, sum = 9 + 9 + 1 = 19, for next step carry = 1
// STEP 3, i = 1, j = -1, index = 1, LOOP will stop
while(i>=0 && j>=0)
{
int sum = a[i] + b[j] + carry;
if(sum>=10)
{
carry = 1;
}
else
{
carry = 0;
}

result[index] = sum%10;

// 0 0 9 8

// both arrows will move towards left
i = i-1;
j = j-1;
index = index-1;
}

// STEP 1, i = 1, j = -1, index = 1, sum = 9 + 1 = 10, carry will be 1, result[1] = 0
// STEP 2, i = 0, j = -1, index = 0, sum = 9 + 1 = 10, carry will be 1, result[0] = 0
// STEP 3, i = -1, j = -1, index = -1, THE LOOP will stop
while(i>=0) // first array is remaining but second array is finished
{
int sum = a[i] + carry;
if(sum>=10)
{
carry = 1;
}
else
{
carry = 0;
}
result[index] = sum%10;

// both arrows will move towards left
i = i-1;
index = index-1;
}

while(j>=0) // first array is finished but second array is remaining
{
int sum = b[j] + carry;
if(sum>=10)
{
carry = 1;
}
else
{
carry = 0;
}
result[index] = sum%10;

// both arrows will move towards left
j = j-1;
index = index-1;
}

// result = [0, 0, 9, 8]

// After addition if carry is 1 (we need to increase the size)
if(carry == 1)
{

// answer = [1, 0, 0, 9, 8]

// we will copy all values from result array to the answer array

// STEP 1, i=0, i+1 = 1, answer[1] = result[0]
// STEP 2, i=1, i+1 = 2, answer[2] = result[1]
// STEP 3, i=2, i+1 = 3, answer[3] = result[2]
// STEP 4, i=3, i+1 = 4, answer[4] = result[3]

for(int k=0; k<size; k=k+1)
{
}

}

return result;
}

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n1 = sc.nextInt();
int[] arr1 = new int[n1];
for (int i = 0; i < n1; i++) arr1[i] = sc.nextInt();

int n2 = sc.nextInt();
int[] arr2 = new int[n2];
for (int i = 0; i < n2; i++) arr2[i] = sc.nextInt();
sc.close();

int[] res = calSum(arr1, arr2, n1, n2);
for (int i : res) System.out.println(i);
}
}```