Numeral 7

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

//Write a program to convert from any numeral system of given base s to any other numeral system of base d (2 ≤ s, d ≤  16).

class ConvertAnyToAny
{
    static void Main()
    {
        Console.Write("Enter the entrance number base: ");
        int s = int.Parse(Console.ReadLine());
        Console.Write("Enter a number in the chosen numeral system: ");
        string numberInput = Console.ReadLine();
        Console.Write("Enter the result number base: ");
        int d = int.Parse(Console.ReadLine());
        int decimalInput = SToDecimal(numberInput, s);
        DecimalToD(decimalInput, d);
    }

    static void DecimalToD(int number,int d)
    {
        StringBuilder printNum = new StringBuilder();
        while (number != 0)
        {
            char addingChar = ' ';
            switch (number % d)
            {
                case 0: addingChar = '0'; break;
                case 1: addingChar = '1'; break;
                case 2: addingChar = '2'; break;
                case 3: addingChar = '3'; break;
                case 4: addingChar = '4'; break;
                case 5: addingChar = '5'; break;
                case 6: addingChar = '6'; break;
                case 7: addingChar = '7'; break;
                case 8: addingChar = '8'; break;
                case 9: addingChar = '9'; break;
                case 10: addingChar = 'A'; break;
                case 11: addingChar = 'B'; break;
                case 12: addingChar = 'C'; break;
                case 13: addingChar = 'D'; break;
                case 14: addingChar = 'E'; break;
                case 15: addingChar = 'F'; break;
            }
            printNum.Insert(0,addingChar);
            number /= d;
        }
        Console.WriteLine(printNum.ToString());
    }

    static int SToDecimal(string input,int s)
    {
        int result = 0;
        for (int i = 0; i < input.Length; i++)
        {
            result += Powing(input[input.Length-(i+1)], i, s);
        }
        return result;
    }

    static int Powing(char inputInt, int i, int s)
    {
        if (inputInt != '0')
        {
            int result = 1;
            switch (inputInt)
            {
                case '0': result = 0; break;
                case '1': result = 1; break;
                case '2': result = 2; break;
                case '3': result = 3; break;
                case '4': result = 4; break;
                case '5': result = 5; break;
                case '6': result = 6; break;
                case '7': result = 7; break;
                case '8': result = 8; break;
                case '9': result = 9; break;
                case 'A': result = 10; break;
                case 'B': result = 11; break;
                case 'C': result = 12; break;
                case 'D': result = 13; break;
                case 'E': result = 14; break;
                case 'F': result = 15; break;
            }
            for (int g = 0; g < i; g++)
            {
                result *= s;
            }
            return result;
        }
        return 0;
    }
}