#pragma warning disable IDE0011
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using static System.Convert;
using static System.Math;
using static Extentions;

class IO
{
    int idx;
    string[] line;

    public void R(params char[] sep) { line = Console.ReadLine().Split(sep); idx = 0; }
    public string S => line[idx++];
    public string[] Ss => line.Skip(idx++).ToArray();
    public char C => char.Parse(line[idx++]);
    public char[] Cs => line.Skip(idx++).Select(char.Parse).ToArray();
    public int I => int.Parse(line[idx++]);
    public int[] Is => line.Skip(idx++).Select(int.Parse).ToArray();
    public long L => long.Parse(line[idx++]);
    public long[] Ls => line.Skip(idx++).Select(long.Parse).ToArray();
    public double F => double.Parse(line[idx++]);
    public double[] Fs => line.Skip(idx++).Select(double.Parse).ToArray();
    public decimal D => decimal.Parse(line[idx++]);
    public decimal[] Ds => line.Skip(idx++).Select(decimal.Parse).ToArray();
    public BigInteger B => BigInteger.Parse(line[idx++]);
    public BigInteger[] Bs => line.Skip(idx++).Select(BigInteger.Parse).ToArray();

    public void Write<T>(params T[] xs)
    {
        Console.Write(xs.First());
        foreach (var x in xs.Skip(1)) Console.Write(" " + x);
        Console.WriteLine();
    }
    public void Write(params object[] xs)
    {
        Console.Write(xs.First());
        foreach (var x in xs.Skip(1)) Console.Write(" " + x);
        Console.WriteLine();
    }
}

static class Extentions
{
    public static long Gcd(long x, long y)
    {
        long r;
        while ((r = x % y) != 0) { x = y; y = r; }
        return y;
    }

    public static long Lcm(long x, long y) => x * y / Gcd(x, y);
}

public struct Rational : IComparable<Rational>, IEquatable<Rational>
{
    long numer;
    long denom;
    public long Numer { get { this.Reduce(); return numer; } }
    public long Denom { get { this.Reduce(); return denom; } }

    public int Sign => numer.CompareTo(0) * denom.CompareTo(0);

    public Rational(long numer, long denom)
    {
        this.numer = numer;
        this.denom = denom;
    }

    void Reduce()
    {
        if (numer == 0) { denom = 1; return; }
        var d = Gcd(numer, denom);
        numer /= d; denom /= d;
        if (denom < 0) { numer *= -1; denom *= -1; }
    }

    public Rational Invert() => new Rational(denom, numer);

    public static Rational operator -(Rational r)
        => new Rational(-r.numer, r.denom);

    public static Rational operator +(Rational left, Rational right)
    {
        left.Reduce(); right.Reduce();
        var d = Lcm(left.denom, right.denom);
        var n = checked(left.numer * d / left.denom + right.numer * d / right.denom);
        return new Rational(n, d);
    }

    public static Rational operator *(Rational left, Rational right)
    {
        left.Reduce(); right.Reduce();
        var n = checked(left.numer * right.numer);
        var d = checked(left.denom * right.denom);
        return new Rational(n, d);
    }

    public static Rational operator -(Rational left, Rational right)
        => left + -right;

    public static Rational operator /(Rational left, Rational right)
        => left * right.Invert();

    public static bool operator ==(Rational left, Rational right)
        => left.Equals(right);

    public static bool operator !=(Rational left, Rational right)
        => !left.Equals(right);

    public static bool operator <(Rational left, Rational right)
        => left.CompareTo(right) < 0;

    public static bool operator >(Rational left, Rational right)
        => left.CompareTo(right) > 0;

    public static bool operator <=(Rational left, Rational right)
        => left < right || left == right;

    public static bool operator >=(Rational left, Rational right)
        => left > right || left == right;

    public static implicit operator Rational(long x) => new Rational(x, 1);

    public int CompareTo(Rational other) => (this - other).Sign;

    public bool Equals(Rational other)
    {
        var r = this / other;
        return r.numer == r.denom;
    }

    public override bool Equals(object obj)
    {
        if (!(obj is Rational)) return false;
        var r = (Rational)obj / this;
        return r.numer == r.denom;
    }

    public override int GetHashCode()
        => this.Numer.GetHashCode() ^ this.Denom.GetHashCode();

    public override string ToString() => $"{this.Numer} / {this.Denom}";
}

static class Program
{
    public static void Main()
    {
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        Solve(new IO());
        Console.Out.Flush();
    }

    public static void Solve(IO io)
    {
        io.R();
        var b = io.Ls;

        var d = new Rational(b[0] * b[2] - b[1] * b[1], b[0] - b[1]);
        var r = b[0] != 0 ? -(d - b[1]) / b[0] : -(d - b[2]) / b[1];

        io.Write((r * b[2] + d).Numer);
    }
}