#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define PI 3.1415926535897932384626
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define br '\n'
#define FOR(i, a, b) for(int i=int(a);i<=int(b);++i)
#define FORR(i, a, b) for(int i=int(a);i>=int(b);--i)
#define TR(it, x) for(auto it = x.begin(); it != x.end(); it++)
#define TRR(it, x) for(auto it = x.rbegin(); it != x.rend(); it++)
#define deb(x) cout<<#x<<"-"<<x<<"\n"
typedef pair<int, int> pii;
typedef pair<float, float> pff;
typedef vector<int> vi;
typedef vector<float> vf;
typedef vector<pii> vpii;
typedef vector<vi> vvi; 
typedef stack<int> si;
typedef queue<int> qi;
mt19937_64 rang(chrono::high_resolution_clock::now().time_since_epoch().count());
const int mod = 1e7;
const int MAX = 1e8;

/* ========== START HERE ========= */
string multiply(string num1, string num2){
    int n1 = num1.size();
    int n2 = num2.size();
    if (n1 == 0 || n2 == 0)
        return "0";
    vector<int> result(n1 + n2, 0);
    int i_n1 = 0;
    int i_n2 = 0;
    for (int i = n1 - 1; i>=0; i--) {
        int carry = 0;
        int n1 = num1[i] - '0';
        i_n2 = 0;
        FORR(j,n2 - 1,0) {
            int n2 = num2[j] - '0';
            int sum = n1 * n2 + result[i_n1 + i_n2] + carry;
            carry = sum / 10;
            result[i_n1 + i_n2] = sum % 10;
 
            i_n2++;
        }
        if (carry > 0)
            result[i_n1 + i_n2] += carry;
        i_n1++;
    }
    int i = result.size() - 1;
    while (i >= 0 && result[i] == 0)
        i--;
    if (i == -1)
        return "0";
    string s = "";
       
    while (i >= 0)
        s += std::to_string(result[i--]);
 
    return s;
}

string findSum(string str1, string str2){
    if (str1.length() > str2.length())
        swap(str1, str2);
    string str = "";
    int n1 = str1.length(), n2 = str2.length();
    reverse(str1.begin(), str1.end());
    reverse(str2.begin(), str2.end());
 
    int carry = 0;
    for (int i=0; i<n1; i++){
        int sum = ((str1[i]-'0')+(str2[i]-'0')+carry);
        str.push_back(sum%10 + '0');
        carry = sum/10;
    }
    FOR(i,n1,n2-1){
        int sum = ((str2[i]-'0')+carry);
        str.push_back(sum%10 + '0');
        carry = sum/10;
    }
    if (carry)
        str.push_back(carry+'0');
    reverse(str.begin(), str.end());
    return str;
}

string fibonacci_modified(string t1,string t2,int n){
    string dp[n+1];
    dp[1]=t1;
    dp[2]=t2;
    FOR(i,3,n){
        dp[i]=findSum(multiply(dp[i-1],dp[i-1]),dp[i-2]);
    }
    return dp[n];
}


void solve() {
    string t1,t2;
    int n;
    cin>>t1>>t2>>n;
    cout<<fibonacci_modified(t1,t2,n);
}

/* ========== THE MAIN ========= */

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    srand(chrono::high_resolution_clock::now().time_since_epoch().count());
    int t=1;
    //scanf("%d",&t);
    while(t--){
        solve();
    }
    return EXIT_SUCCESS;
}