#include <stdio.h>
#include <stdlib.h>
#include <math.h>


int main() {
    int a,b,c,k;

    scanf("%d %d %d %d",&a ,&b,&k,&c);

    int i,j;
    long int sum = 2;
    for (i = 1; i < k; i++){
        sum = sum * 2 ;
    }
    long int pocet;
    pocet= sum * k / 2 % 1000000007;

    printf("%ld\n", pocet);

    return 0;
}