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

typedef long long ll;
typedef pair<int,int> P;

#define p_ary(ary,a,b) do { cout << "["; for (int count = (a);count < (b);++count) cout << ary[count] << ((b)-1 == count ? "" : ", "); cout << "]\n"; } while(0)
#define p_map(map,it) do {cout << "{";for (auto (it) = map.begin();;++(it)) {if ((it) == map.end()) {cout << "}\n";break;}else cout << "" << (it)->first << "=>" << (it)->second << ", ";}}while(0)

template<typename T1,typename T2>ostream& operator<<(ostream& os,const pair<T1,T2>& a) {os << "(" << a.first << ", " << a.second << ")";return os;}

const char newl = '\n';
ll const mod = 1e9+7;

vector<vector<ll>> prod(vector<vector<ll>>& a, vector<vector<ll>>& b, ll mod) {
    vector<vector<ll>> ret(a.size(),vector<ll>(b[0].size(),0));
    for (int i = 0;i < a.size();++i) for (int j = 0;j < b[0].size();++j) for (int k = 0;k < a[0].size();++k) {
        ret[i][j] += a[i][k]*b[k][j];
        ret[i][j] %= mod;
    }
    return ret;
}

int main() {
    ll a,b,n;
    cin >> a >> b >> n;
    vector<vector<ll>> ans(2,vector<ll>(1,0)),c(2,vector<ll>(2));
    ans[0][0] = 2*a;
    ans[1][0] = 2;
    c[0][0] = 2*a;
    c[0][1] = (-a*a+b)%mod;
    c[1][0] = 1;
    c[1][1] = 0;
    if (n == 0) {
        cout << 2 << newl;
        return 0;
    }
    n--;
    while (n) {
        if (n&1) ans = prod(c,ans,mod);
        c = prod(c,c,mod);
        n /= 2;
    }
    cout << (ans[0][0]+mod)%mod << newl;
}