# Smallest N digit number which is a multiple of 5

Given an integer N ≥ 1, the task is to find the smallest N digit number which is a multiple of 5.

Examples:

Input: N = 1
Output: 5

Input: N = 2
Output: 10

Input: N = 3
Output: 100

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

• If N = 1 then the answer will be 5.
• If N > 1 then the answer will be (10(N – 1)) because the series of smallest multiple of 5 will go on like 10, 100, 1000, 10000, 100000, …

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to return the smallest n digit ` `// number which is a multiple of 5 ` `int` `smallestMultiple(``int` `n) ` `{ ` `    ``if` `(n == 1) ` `        ``return` `5; ` `    ``return` `pow``(10, n - 1); ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `n = 4; ` `    ``cout << smallestMultiple(n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java implementation of the approach ` `class` `GFG { ` ` `  `    ``// Function to return the smallest n digit ` `    ``// number which is a multiple of 5 ` `    ``static` `int` `smallestMultiple(``int` `n) ` `    ``{ ` `        ``if` `(n == ``1``) ` `            ``return` `5``; ` `        ``return` `(``int``)(Math.pow(``10``, n - ``1``)); ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` `        ``int` `n = ``4``; ` `        ``System.out.println(smallestMultiple(n)); ` `    ``} ` `} `

## Python3

 `# Python3 implementation of the approach ` ` `  `# Function to return the smallest n digit  ` `# number which is a multiple of 5 ` `def` `smallestMultiple(n): ` ` `  `    ``if` `(n ``=``=` `1``): ` `        ``return` `5` `    ``return` `pow``(``10``, n ``-` `1``) ` ` `  `# Driver code ` `n ``=` `4` `print``(smallestMultiple(n)) `

## C#

 `// C# implementation of the approach ` `using` `System; ` `class` `GFG { ` ` `  `    ``// Function to return the smallest n digit ` `    ``// number which is a multiple of 5 ` `    ``static` `int` `smallestMultiple(``int` `n) ` `    ``{ ` `        ``if` `(n == 1) ` `            ``return` `5; ` `        ``return` `(``int``)(Math.Pow(10, n - 1)); ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `n = 4; ` `        ``Console.Write(smallestMultiple(n)); ` `    ``} ` `} `

## PHP

 ` `

Output:

```1000
```

Time Complexity: O(1)

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