#include <bits/stdc++.h>

 using namespace std;

 typedef __int64 LL;

 struct data {

     LL mat[][];

 };

 LL mod = 1e9 + ;

 data operator *(data a , data b) {

     data res;

     for(int i =  ; i <=  ; ++i) {

         for(int j =  ; j <=  ; ++j) {

             res.mat[i][j] = ;

             for(int k =  ; k <=  ; ++k) {

                 res.mat[i][j] = (a.mat[i][k] * b.mat[k][j] % mod + res.mat[i][j]) % mod;

             }

         }

     }

     return res;

 }

 data operator ^(data a , LL n) {

     data res;

     for(int i =  ; i <=  ; ++i) {

         for(int j =  ; j <=  ; ++j) {

             res.mat[i][j] = i == j;

         }

     }

     while(n) {

         if(n & )

             res = res * a;

         a = a * a;

         n >>= ;

     }

     return res;

 }

 int main()

 {

     LL a , b , n , x;

     cin >> a >> b >> n >> x;

     data temp , res;

     temp.mat[][] = a % mod , temp.mat[][] =  , temp.mat[][] = b % mod, temp.mat[][] = ;

     res.mat[][] = x % mod , res.mat[][] =  , res.mat[][] = res.mat[][] = ;

     temp = temp ^ n;

     res = res * temp;

     cout << res.mat[][] << endl;

     return ;

 }