#include <bits/stdc++.h>
using namespace std;
long long powmod(long long a, long long b) {
  if (b == 0) return 1;
  long long x = powmod(a, b / 2);
  long long y = (x * x) % 1000000007;
  if (b % 2) return (a * y) % 1000000007;
  return y % 1000000007;
}
long long mulmod(long long a, long long b, long long c) {
  long long x = 0, y = a % c;
  while (b > 0) {
    if (b % 2 == 1) {
      x = (x + y) % c;
    }
    y = (y * 2) % c;
    b /= 2;
  }
  return x % c;
}
int main() {
  long long a, b, x, n;
  cin >> a >> b >> n >> x;
  long long nm1, nm2, nm3, nm4, nm5;
  if (a > 1) {
    nm1 = powmod(a, n);
    nm2 = (nm1 - 1 + 1000000007) % 1000000007;
    nm3 = (x * nm1) % 1000000007;
    nm4 = (a - 1 + 1000000007) % 1000000007;
    nm5 = (nm2 * powmod(nm4, 1000000007 - 2)) % 1000000007;
    long long nm6 = (nm3 + (nm5 * b) % 1000000007) % 1000000007;
    cout << nm6 << endl;
  } else
    cout << (x + mulmod(b, n, 1000000007)) % 1000000007 << endl;
  return 0;
}
