#include <bits/stdc++.h>
using namespace std;
long long A, B, n, x;
struct he {
  long long a[4][4];
} ans, base, c;
he mul(he a, he b) {
  for (int i = 1; i <= 2; i++)
    for (int j = 1; j <= 2; j++) c.a[i][j] = 0;
  for (int i = 1; i <= 2; i++)
    for (int j = 1; j <= 2; j++)
      for (int k = 1; k <= 2; k++)
        c.a[i][j] =
            (c.a[i][j] + a.a[i][k] * b.a[k][j] % 1000000007) % 1000000007;
  return c;
}
he get(long long t) {
  if (t == 1) return base;
  he tmp = get(t / 2);
  tmp = mul(tmp, tmp);
  if (t & 1) tmp = mul(tmp, base);
  return tmp;
}
int main() {
  scanf("%lld%lld%lld%lld", &A, &B, &n, &x);
  base.a[1][1] = A;
  base.a[1][2] = B;
  base.a[2][1] = 0;
  base.a[2][2] = 1;
  ans = get(n);
  printf("%lld\n",
         (ans.a[1][1] * x % 1000000007 + ans.a[1][2] +
          ans.a[2][1] * x % 1000000007 + ans.a[2][2] - 1 + 1000000007) %
             1000000007);
}
