include <iostream>
#include <vector>
#include <stdio.h>
#include <iomanip>

using namespace std;

#define ll long double

struct ECUACION
{
    /**
    Para ecuaciones de la forma:
    x = p*A + q*B;
    **/
    ll x, p, q;
};

int main()
{
    vector <ll> a, b, v;

    a = {1, 0};
    b = {0, 1};

    for(int i=1; i<5000; i++)
    {
        a.push_back((a[i]+a[i-1]));
        b.push_back((b[i]+b[i-1]));
    }

    v = vector <ll> (a.size());

    ll posI, valI, posJ, valJ, posN;

    cin >> posI >> valI >> posJ >> valJ >> posN;

    ///Convertir a 0-indexed

    if(posI > posJ)
    {
        swap(posI, posJ);
        swap(valI, valJ);
    }

    ll menorVal = min(posN, min(posI, posJ));

    posI += (-menorVal);
    posJ += (-menorVal);
    posN += (-menorVal);

    v[posI] = valI;
    v[posJ] = valJ;

    ECUACION eq1;

    eq1.x = v[posI];
    eq1.p = a[posI];
    eq1.q = b[posI];

    ECUACION eq2;

    eq2.x = v[posJ];
    eq2.p = a[posJ];
    eq2.q = b[posJ];

    ll numeradorA = (eq1.x*eq2.q) - (eq2.x*eq1.q);
    ll denominadA = (eq1.p*eq2.q) - (eq2.p*eq1.q);
    ll A = numeradorA/denominadA;

    ll numeradorB = (eq2.x - (eq2.p*A));
    ll denominadB = eq2.q;
    ll B = numeradorB/denominadB;

    ll resN = A*a[posN] + B*b[posN];
    cout << setprecision(200) << resN << endl;

    return 0;
}