Consider a linear function f(x) = Ax + B. Let's define g(0)(x) = x and g(n)(x) = f(g(n - 1)(x)) for n > 0. For the given integer values A, B, n and x find the value of g(n)(x) modulo 109 + 7.

Input

The only line contains four integers A, B, n and x (1 ≤ A, B, x ≤ 109, 1 ≤ n ≤ 1018) — the parameters from the problem statement.

Note that the given value n can be too large, so you should use 64-bit integer type to store it. In C++ you can use the long long integer type and in Java you can use long integer type.

Output

Print the only integer s — the value g(n)(x) modulo 109 + 7.

Examples

Input

3 4 1 1


Output

7


Input

3 4 2 1


Output

25


Input

3 4 3 1


Output

79
/*
 * Code Author: Akshay Miterani
 * DA-IICT
 */
import java.io.*;
import java.math.BigInteger;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.util.*;


public class MainC {

	static double eps=(double)1e-7;
	static long mod=(int)1e9+7;
	public static void main(String args[]){
		InputReader in = new InputReader(System.in);
		OutputStream outputStream = System.out;
		PrintWriter out = new PrintWriter(outputStream);
		//----------My Code----------
		long a=in.nextLong();
		long b=in.nextLong();
		long n=in.nextLong();
		long x=in.nextLong();
		long ans1=(modulo(a, n, mod)*x%mod)%mod;
		long ans2=((b*(modulo(a, n, mod)-1))%mod*modulo(a-1, mod-2, mod))%mod;
		if(a==(long)1){
			ans2=((b%mod)*(n%mod));
			ans2%=mod;
		}
		long ans=ans1+ans2;
		ans%=mod;
		System.out.println(ans);
		out.close();
		//---------------The End------------------

	}

	public static void debug(Object... o) {
		System.out.println(Arrays.deepToString(o));
	}

	static long round(long x){
		if(x%10<5){
			x/=10;
			x*=10;
			return x;
		}
		else{
			x/=10;
			x++;
			x*=10;
			return x;
		}
	}

	static long modulo(long a,long b,long c) {
		long x=1;
		long y=a;
		while(b > 0){
			if(b%2 == 1){
				x=(x*y)%c;
			}
			y = (y*y)%c; // squaring the base
			b /= 2;
		}
		return  x%c;
	}
	
	static long gcd(long x, long y)
	{
		if(x==0)
			return y;
		if(y==0)
			return x;
		long r=0, a, b;
		a = (x > y) ? x : y; // a is greater number
		b = (x < y) ? x : y; // b is smaller number
		r = b;
		while(a % b != 0)
		{
			r = a % b;
			a = b;
			b = r;
		}
		return r;
	}
	static class Pair implements Comparable<Pair>{
		Double x;
		int ind;
		Pair(double xx,int yy){
			x=xx;
			ind=yy;
		}
		@Override
		public int compareTo(Pair o) {
			return Double.compare(this.x, o.x);
		}
	}

	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream inputstream) {
			reader = new BufferedReader(new InputStreamReader(inputstream));
			tokenizer = null;
		}

		public String nextLine(){
			String fullLine=null;
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					fullLine=reader.readLine();
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
				return fullLine;
			}
			return fullLine;
		}
		public String next() {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		}
		public long nextLong() {
			return Long.parseLong(next());
		}
		public int nextInt() {
			return Integer.parseInt(next());
		}
	}
} 