using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using static System.Console;
using static System.Convert;
using static System.Math;
using static Extentions;

class IO
{
    int idx;
    string[] input = In.ReadToEnd().Split(new[] { " ", "\n", "\r" },
        StringSplitOptions.RemoveEmptyEntries);

    T Get<T>(Func<string, T> parser) => parser(input[idx++]);

    public string S => Get(s => s);
    public char C => Get(char.Parse);
    public int I => Get(int.Parse);
    public long L => Get(long.Parse);
    public double F => Get(double.Parse);
    public decimal D => Get(decimal.Parse);
    public BigInteger B => Get(BigInteger.Parse);

    T[] Gets<T>(int n, Func<string, T> parser)
        => input.Skip((idx += n) - n).Take(n).Select(parser).ToArray();

    public string[] Ss(int n) => Gets(n, s => s);
    public char[] Cs(int n) => Gets(n, char.Parse);
    public int[] Is(int n) => Gets(n, int.Parse);
    public long[] Ls(int n) => Gets(n, long.Parse);
    public double[] Fs(int n) => Gets(n, double.Parse);
    public decimal[] Ds(int n) => Gets(n, decimal.Parse);
    public BigInteger[] Bs(int n) => Gets(n, BigInteger.Parse);

    public void Write<T>(params T[] xs) => WriteLine(string.Join(" ", xs));
    public void Write(params object[] xs) => WriteLine(string.Join(" ", xs));
}

interface IInteger<T>
{
    T MinusOne { get; }
    T One { get; }
    T Zero { get; }

    T Add(T left, T right);
    int Compare(T left, T right);
    T Divide(T dividend, T divisor);
    T Multiply(T left, T right);
    T Negate(T value);
    T Remainder(T dividend, T divisor);
    T Subtract(T left, T right);
}

static class Integer<T>
{
    static IInteger<int> i = new IntOperations();
    static IInteger<long> l = new LongOperations();
    static IInteger<BigInteger> bi = new BigIntegerOperations();

    public static IInteger<T> Default
    {
        get
        {
            if (typeof(T) == typeof(int)) return (IInteger<T>)i;
            else if (typeof(T) == typeof(long)) return (IInteger<T>)l;
            else if (typeof(T) == typeof(BigInteger)) return (IInteger<T>)bi;
            else throw new NotSupportedException();
        }
    }
}

class IntOperations : IInteger<int>
{
    public int MinusOne => -1;
    public int One => 1;
    public int Zero => 0;

    public int Add(int left, int right) => checked(left + right);
    public int Compare(int left, int right) => left.CompareTo(right);
    public int Divide(int dividend, int divisor) => dividend / divisor;
    public int Multiply(int left, int right) => checked(left * right);
    public int Negate(int value) => checked(-value);
    public int Remainder(int dividend, int divisor) => dividend % divisor;
    public int Subtract(int left, int right) => checked(left - right);
}

class LongOperations : IInteger<long>
{
    public long MinusOne => -1;
    public long One => 1;
    public long Zero => 0;

    public long Add(long left, long right) => checked(left + right);
    public int Compare(long left, long right) => left.CompareTo(right);
    public long Divide(long dividend, long divisor) => dividend / divisor;
    public long Multiply(long left, long right) => checked(left * right);
    public long Negate(long value) => checked(-value);
    public long Remainder(long dividend, long divisor) => dividend % divisor;
    public long Subtract(long left, long right) => checked(left - right);
}

class BigIntegerOperations : IInteger<BigInteger>
{
    public BigInteger MinusOne => BigInteger.MinusOne;
    public BigInteger One => BigInteger.One;
    public BigInteger Zero => BigInteger.Zero;

    public BigInteger Add(BigInteger left, BigInteger right)
        => BigInteger.Add(left, right);
    public int Compare(BigInteger left, BigInteger right)
        => BigInteger.Compare(left, right);
    public BigInteger Divide(BigInteger dividend, BigInteger divisor)
        => BigInteger.Divide(dividend, divisor);
    public BigInteger Multiply(BigInteger left, BigInteger right)
        => BigInteger.Multiply(left, right);
    public BigInteger Negate(BigInteger value)
        => BigInteger.Negate(value);
    public BigInteger Remainder(BigInteger dividend, BigInteger divisor)
        => BigInteger.Remainder(dividend, divisor);
    public BigInteger Subtract(BigInteger left, BigInteger right)
        => BigInteger.Subtract(left, right);
}

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

    IInteger<T> i;

    public int Sign => i.Compare(numer, i.Zero) * i.Compare(denom, i.Zero);

    public Rational(T numer, T denom)
    {
        this.numer = numer;
        this.denom = denom;
        i = Integer<T>.Default;
    }

    void Reduce()
    {
        if (i.Compare(numer, i.Zero) == 0) { denom = i.One; return; }
        var d = Gcd(numer, denom, i);
        numer = i.Divide(numer, d);
        denom = i.Divide(denom, d);
        if (i.Compare(denom, i.Zero) < 0)
        {
            numer = i.Negate(numer);
            denom = i.Negate(denom);
        }
    }

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

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

    public static Rational<T> operator +(Rational<T> left, Rational<T> right)
    {
        var i = left.i;
        left.Reduce(); right.Reduce();
        var d = Lcm(left.denom, right.denom, i);
        var n = i.Add(i.Divide(i.Multiply(left.numer, d), left.denom),
            i.Divide(i.Multiply(right.numer, d), right.denom));
        return new Rational<T>(n, d);
    }

    public static Rational<T> operator *(Rational<T> left, Rational<T> right)
    {
        var i = left.i;
        left.Reduce(); right.Reduce();
        var n = i.Multiply(left.numer, right.numer);
        var d = i.Multiply(left.denom, right.denom);
        return new Rational<T>(n, d);
    }

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

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

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

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

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

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

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

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

    public static implicit operator Rational<T>(T x)
        => new Rational<T>(x, Integer<T>.Default.One);

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

    public bool Equals(Rational<T> other)
    {
        var r = this / other;
        return r.i.Compare(r.numer, r.denom) == 0;
    }

    public override bool Equals(object obj)
    {
        if (!(obj is Rational<T>)) return false;
        var r = (Rational<T>)obj / this;
        return r.i.Compare(r.numer, r.denom) == 0;
    }

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

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

static partial class Extentions
{
    public static T Gcd<T>(T x, T y, IInteger<T> integer)
    {
        T r;
        while (integer.Compare((r = integer.Remainder(x, y)), integer.Zero)
            != 0) { x = y; y = r; }
        return y;
    }

    public static T Lcm<T>(T x, T y, IInteger<T> integer)
        => integer.Multiply(integer.Divide(x, Gcd(x, y, integer)), y);
}

static class Program
{
    public static void Main()
    {
        var sw = new StreamWriter(OpenStandardOutput()) { NewLine = "\n" };
#if DEBUG
        sw.AutoFlush = true;
#else
        sw.AutoFlush = false;
#endif
        SetOut(sw);
        Solve(new IO());
        Out.Flush();
    }

    static void Solve(IO io)
    {
        var b = io.Ls(3);

        var d = new Rational<long>(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);
    }
}