#include <stdio.h>

int main(void) {
	int N,count=0,X;
	scanf("%d",&N);
	int A[N+1];
	for(int i=2;i<N+1;i++){
		scanf("%d",&A[i]);
	}
	scanf("%d",&X);
	
	while(A[X] > 0){
		X = A[X];
		count++;
	}
	printf("%d",count);
	return 0;
}