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

namespace ConsoleApplication4 {
    class Program {
        static void Main() {
            int[] abcd = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
            Console.WriteLine(((((abcd[0] % abcd[3]) * abcd[1]) % abcd[3]) * abcd[2]) % abcd[3]);
        }
    }
}