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Find the remainder when First digit of a number is divided by its Last digit
• Last Updated : 21 Apr, 2021

Given a number N, find the remainder when the first digit of N is divided by its last digit.
Examples:

```Input: N = 1234
Output: 1
First digit = 1
Last digit = 4
Remainder = 1 % 4 = 1

Input: N = 5223
Output: 2
First digit = 5
Last digit = 3
Remainder = 5 % 3 = 2```

Approach: Find the first digit and the last digit of the number. Find then the remainder when the first digit is divided by the last digit.
Below is the implementation of the above approach:

## C++

 `// C++ program to find the remainder``// when the First digit of a number``// is divided by its Last digit` `#include ``using` `namespace` `std;` `// Function to find the remainder``void` `findRemainder(``int` `n)``{``    ``// Get the last digit``    ``int` `l = n % 10;` `    ``// Get the first digit``    ``while` `(n >= 10)``        ``n /= 10;``    ``int` `f = n;` `    ``// Compute the remainder``    ``int` `remainder = f % l;` `    ``cout << remainder << endl;``}` `// Driver code``int` `main()``{` `    ``int` `n = 5223;` `    ``findRemainder(n);` `    ``return` `0;``}`

## Java

 `// Java program to find the remainder``// when the First digit of a number``// is divided by its Last digit``class` `GFG``{``    ` `// Function to find the remainder``static` `void` `findRemainder(``int` `n)``{``    ``// Get the last digit``    ``int` `l = n % ``10``;` `    ``// Get the first digit``    ``while` `(n >= ``10``)``        ``n /= ``10``;``    ``int` `f = n;` `    ``// Compute the remainder``    ``int` `remainder = f % l;` `    ``System.out.println(remainder);``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``int` `n = ``5223``;``    ``findRemainder(n);``}``}` `// This code is contributed by Code_Mech`

## Python3

 `# Python3 program to find the remainder``# when the First digit of a number``# is divided by its Last digit` `# Function to find the remainder``def` `findRemainder(n):``    ` `    ``# Get the last digit``    ``l ``=` `n ``%` `10`` ` `    ``# Get the first digit``    ``while` `(n >``=` `10``):``        ``n ``/``/``=` `10``    ``f ``=` `n` `    ``# Compute the remainder``    ``remainder ``=` `f ``%` `l` `    ``print``(remainder)` `# Driver code``n ``=` `5223` `findRemainder(n)` `# This code is contributed by Mohit Kumar`

## C#

 `// C# program to find the remainder``// when the First digit of a number``// is divided by its Last digit``using` `System;` `class` `GFG``{``    ` `// Function to find the remainder``static` `void` `findRemainder(``int` `n)``{``    ``// Get the last digit``    ``int` `l = n % 10;` `    ``// Get the first digit``    ``while` `(n >= 10)``        ``n /= 10;``    ``int` `f = n;` `    ``// Compute the remainder``    ``int` `remainder = f % l;` `    ``Console.WriteLine(remainder);``}` `// Driver code``public` `static` `void` `Main()``{``    ``int` `n = 5223;``    ``findRemainder(n);``}``}` `// This code is contributed by Code_Mech`

## Javascript

 ``
Output:
`2`

Time Complexity: O(L ) where L is length of number in decimal representation

Auxiliary Space: O(1)

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