题解 | #计算某字母出现次数#

using System;

public class Program
{
    public static void Main()
    {
        string input1 = Console.ReadLine().ToLower();
        string input2 = Console.ReadLine().ToLower();
        int count = 0;
        while(input1.Contains(input2))
        {
            int index = input1.IndexOf(input2);
            input1 = input1.Substring(index + 1);
            count++;
        }        
        Console.WriteLine(count);
    }
}