#include <stdio.h>

int main(void) {
    int n;
    int parent[100];
    int target;
    int distance = 0;

    scanf("%d", &n);

    for (int i = 1; i <= n; i++) {
        scanf("%d", &parent[i]);
    }

    scanf("%d", &target);

    while (parent[target] != 0) {
        target = parent[target];
        distance++;
    }

    printf("%d\n", distance);

    return 0;
}