using System;
using System.Linq;
using System.Linq.Expressions;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Int32;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var l = sc.Long();
            var b = sc.Long();
            var r = sc.Long();
            var t = sc.Long();
            var d = sc.Long();
            l = Math.Max(l, -d);
            r = Math.Min(r, d);
            t = Math.Min(t, d);
            b = Math.Max(b, -d);

            if (r < l || t < b)
            {
                IO.Printer.Out.WriteLine(0);
                return;
            }
            var ans = 0L;

            var xs = new List<long>() { l, r, d - Math.Abs(t), Math.Abs(t) - d, Math.Abs(b) - d, d - Math.Abs(b) };
            xs = xs.Distinct().Where(x => l <= x && x <= r).ToList();
            xs.Sort();
            var xt = Math.Min(t, Math.Abs(d - Math.Abs(l)));
            var xb = Math.Max(b, -Math.Abs(d - Math.Abs(l)));
            ans += (xt - xb + 1);
            for (int i = 1; i < xs.Count; i++)
            {
                var dx = xs[i] - xs[i - 1];
                var nt = Math.Min(t, Math.Abs(d - Math.Abs(xs[i])));
                var nb = Math.Max(b, -Math.Abs(d - Math.Abs(xs[i])));
                if (nt < nb) break;
                var s2 = ((nt - nb) + (xt - xb)) * dx;
                var bb = (nt - nb + 1) + (xt - xb + 1);
                bb += 2 * (dx - 1);
                //2s-b+2=2i
                ans += bb;
                ans += (s2 - bb + 2) / 2;
                ans -= (xt - xb) + 1;
                xt = nt;
                xb = nb;
            }
            IO.Printer.Out.WriteLine(ans);

        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<T>(int n, Func<int, T> f) { var a = new T[n]; for (int i = 0; i < n; ++i) a[i] = f(i); return a; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}
#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer : StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion

#region FFT
static public partial class MathEX
{
    static private void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    [System.Diagnostics.Conditional("DEBUG")]
    static void check(int n)
    {
        int k = 1;
        while (k < n) k *= 2;
        Debug.Assert(k == n);
    }
    /// <summary>
    /// 畳み込み演算(g*h)(x)=ΣΣA_iB_jx^{i+j}をする．
    /// </summary>
    static public Complex[] Convolute(Complex[] A, Complex[] B)
    {
        var n = A.Length;
        var ret = new Complex[n];
        FFT(A); FFT(B);
        for (int i = 0; i < n; i++)
            ret[i] = A[i] * B[i];
        InvFFT(ret);
        return ret;
    }
    /// <summary>
    /// Stockham FFT
    /// </summary>
    static public void FFT(Complex[] a)
    {
        check(a.Length);
        var buf = new Complex[a.Length];
        fft0(a.Length, 1, false, a, buf);
    }
    /// <summary>
    /// Stockham FFT
    /// </summary>
    static public void InvFFT(Complex[] a)
    {
        check(a.Length);
        var buf = new Complex[a.Length];
        for (int i = 0; i < a.Length; i++)
            a[i] = Complex.Conjugate(a[i]);
        fft0(a.Length, 1, false, a, buf);
        for (int i = 0; i < a.Length; i++)
            a[i] = Complex.Conjugate(a[i]) / a.Length;
    }
    static private void fft0(int n, int s, bool eo, Complex[] x, Complex[] y)
    {
        while (n >= 2)
        {
            int m = n / 2;
            var theta0 = 2 * Math.PI / n;
            if (n == 2)
            {
                var z = eo ? y : x;
                for (int q = 0; q < s; q++)
                {
                    var a = x[q + 0];
                    var b = x[q + s];
                    z[q + 0] = a + b;
                    z[q + s] = a - b;
                }
                return;
            }
            else
            {
                for (int p = 0; p < m; p++)
                {
                    var wp = new Complex(Math.Cos(p * theta0), -Math.Sin(p * theta0));
                    for (int q = 0; q < s; q++)
                    {
                        var a = x[q + s * p];
                        var b = x[q + s * (p + m)];
                        y[q + s * (2 * p)] = a + b;
                        y[q + s * (2 * p + 1)] = (a - b) * wp;
                    }
                }
                //fft0(n / 2, 2 * s, !eo, y, x);
                n /= 2; s *= 2; eo ^= true; Swap(ref y, ref x);
            }
        }
    }

}

#endregion