using System;
using System.Collections.Generic;
using System.Linq;

public class Test
{
	public static void Main()
	{
		var x = Console.ReadLine()
			.Split(' ')
			.Select(n => int.Parse(n))
			.ToList();
		int ans = (x[0] * x[1] * x[2]) % x[3];
		Console.WriteLine(ans);
	}
}