#include <bits/stdc++.h>
using namespace std;
using ll = long long;

struct yuri {
    ll num,den;
    yuri() : num(0),den(1) {}
    yuri(ll a) : num(a),den(1){}
    yuri(ll a,ll b) : num(a),den(b){safe();}
    void safe(){
        if(den<0)den*=-1,num*=-1;
        ll v=__gcd(abs(num),den);
        num/=v,den/=v;
    }
    yuri& operator++() {num+=den;return *this;}
    yuri& operator--() {num-=den;return *this;}
    yuri& operator+=(const yuri& rhs) {
        num=num*rhs.den+den*rhs.num;
        den=den*rhs.den;
        safe();
        return *this;
    }
    yuri& operator-=(const yuri& rhs) {
        num=num*rhs.den-den*rhs.num;
        den=den*rhs.den;
        safe();
        return *this;
    }
    yuri& operator*=(const yuri& rhs) {
        num=num*rhs.num;
        den=den*rhs.den;
        safe();
        return *this;
    }
    yuri& operator/=(const yuri& rhs) {
        num=num*rhs.den;
        den=den*rhs.num;
        safe();
        return *this ; 
    }
    yuri operator+() const { return *this; }
    yuri operator-() const { return yuri() - *this; }
    friend yuri operator+(const yuri& lhs, const yuri& rhs) {
        return yuri(lhs) += rhs;
    }
    friend yuri operator-(const yuri& lhs, const yuri& rhs) {
        return yuri(lhs) -= rhs;
    }
    friend yuri operator*(const yuri& lhs, const yuri& rhs) {
        return yuri(lhs) *= rhs;
    }
    friend yuri operator/(const yuri& lhs, const yuri& rhs) {
        return yuri(lhs) /= rhs;
    }
    friend bool operator==(const yuri& lhs, const yuri& rhs) {
        return (lhs.num==rhs.num&&lhs.den==rhs.den);
    }
    friend bool operator!=(const yuri& lhs, const yuri& rhs) {
        return (lhs.num!=rhs.num||lhs.den!=rhs.den);
    }
    friend bool operator<(const yuri& lhs, const yuri& rhs) {
        return (lhs.num*rhs.den<lhs.den*rhs.num);
    }
    friend bool operator<=(const yuri& lhs, const yuri& rhs) {
        return (lhs.num*rhs.den<=lhs.den*rhs.num);
    }
    friend bool operator>(const yuri& lhs, const yuri& rhs) {
        return (lhs.num*rhs.den>lhs.den*rhs.num);
    }
    friend bool operator>=(const yuri& lhs, const yuri& rhs) {
        return (lhs.num*rhs.den>=lhs.den*rhs.num);
    }
    friend ostream& operator << (ostream &os, const yuri& rhs) noexcept {
        if(rhs.den==1)return os << rhs.num;
        return os << rhs.num << '/' << rhs.den;
    }
};

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    vector<ll> b(3);
    for(auto &&v:b)cin >> v;
    ll d0 = b[1] - b[0], d1 = b[2] - b[1];
    yuri r(d1, d0), d = b[1] - b[0] * r;
    cout << r * b[2] + d << endl;
}