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

signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);

    
    ll mod = 1e9+7;
    ll a,b,n;
    cin>>a>>b>>n;
    ll x[3];
    x[0]=0,x[1]=1,x[2]=a;
    for(int i=3;i<=n;i++){
        x[i%3] = (a*x[(i+2)%3])%mod + (b*x[(i+1)%3])%mod;
        x[i%3] %= mod;
        if(i==n){
            cout << x[i%3] << "\n";
            return 0;
        } 
    }



}