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();
            long ans = abcd[0];
            ans *= abcd[1];
            ans %= abcd[3];
            ans *= abcd[2];
            ans %= abcd[3];
            Console.WriteLine(ans);
           
           }
    }
}