using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var count = c[0] * (c[1] - c[2]);
        var ans = 0;
        var x = 0;
        for (var i = 1; i <= count; ++i)
        {
            var p = 0;
            if (i == 1) p = c[3];
            else if (i % 10 != 0) p = x;
            else if (c[4] <= x) p = x - c[4];
            else p = x;
            ans += p;
            x = p;
        }
        WriteLine(ans);
    }
    static List<int> PList(int n)
    {
        var ans = new List<int>();
        var rev = new List<int>();
        for (var i = 1; i * i <= n; ++i)
        {
            if (n % i == 0)
            {
                ans.Add(i);
                if (i * i < n) rev.Add(n / i);
            }
        }
        rev.Reverse();
        ans.AddRange(rev);
        return ans;
    }
}