#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define INF 1000000000
#define mod 1000000007
using ll=long long;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

vector<vector<ll>> matplus_mod(vector<vector<ll>> a,vector<vector<ll>> b){
    assert(a.size()==b.size() and a[0].size()==b[0].size());
    for(int i=0;i<a.size();i++){
        for(int j=0;j<a[0].size();j++){
            a[i][j]+=b[i][j];
            if(a[i][j]>=mod) a[i][j]-=mod;
        }
    }
    return a;
}
 
vector<vector<ll>> matminus_mod(vector<vector<ll>> a,vector<vector<ll>> b){
    assert(a.size()==b.size() and a[0].size()==b[0].size());
    for(int i=0;i<a.size();i++){
        for(int j=0;j<a[0].size();j++){
            a[i][j]-=b[i][j];
            if(a[i][j]<0) a[i][j]+=mod;
        }
    }
    return a;
}
 
vector<vector<ll>> matmul_mod(vector<vector<ll>> a,vector<vector<ll>> b){
    assert(a[0].size()==b.size());
    int n=b.size();
    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<n;k++){
                ret[i][j]+=a[i][k]*b[k][j]%mod;
                ret[i][j]%=mod;
            }
        }
    }
    return ret;
}
 
vector<vector<ll>> matpow_mod(vector<vector<ll>> a,ll k){
    assert(a.size()==a[0].size());
    int n=a.size();
    vector<vector<ll>> ret(n,vector<ll>(n,0));
    for(int i=0;i<n;i++) ret[i][i]=1;
    while(k>0){
        if(k&1) ret=matmul_mod(ret,a);
        a=matmul_mod(a,a);
        k>>=1;
    }
    return ret;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    ll a,b,n;cin>>a>>b>>n;
    vector<vector<ll>> mat(2,vector<ll>(2));
    mat[0][0]=a;mat[0][1]=b;
    mat[1][0]=1;mat[1][1]=0;
    mat=matpow_mod(mat,n);
    vector<vector<ll>> m0(2,vector<ll>(1));
    m0[0][0]=1;m0[1][0]=0;
    
    auto ans=matmul_mod(mat,m0);
    cout<<ans[1][0]<<endl;
    return 0;
}