#include<bits//stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define req(i,n) for(int i = 1;i <=  n; i++)
#define rrep(i,n) for(ll i = n-1;i >= 0;i--)
#define ALL(obj) begin(obj), end(obj)
#define RALL(a) rbegin(a),rend(a)
typedef long long ll;
typedef long double ld;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1e18;
ll mod = 1e9+7;
typedef vector<ll> vec;
typedef vector<vec> mat;
mat mul(mat& a, mat& b) {
	mat c(a.size(), vec(b[0].size(),0));
	rep(i, a.size()) {
		rep(k, b.size()) {
			rep(j, b[0].size()) {
				c[i][j] =(c[i][j] + a[i][k] * b[k][j])% mod;
			}
		}
	}return c;
}
mat mpow(mat a, ll n) {
	mat b(a.size(), vec(a.size(),0));
	rep(i, a.size()) b[i][i] = 1;
	while (n > 0) {
		if (n & 1) b = mul(b, a);
		a = mul(a, a);
		n >>= 1;
	}return b;
}
int main(){
   int a,b,n;cin >>a >>b >>n;
   if(n==0||n==1) cout << n <<endl;
   else{
       mat m = {{a,b},{1,0}};
       m = mpow(m,n-1);
       cout << m[0][0]<<endl;
   }
}