#include <stdio.h>
#include <string.h>

int main(void) {
	int n;
	scanf("%d", &n);
	
	char key[1000];
	scanf("%s", key);
	int len_key = strlen(key);
	
	int idx = -1;
	int min = 1e9;
	
	for(int i = 1; i <= n; i++){
		char str[2000];
		scanf("%s", str);
		int len_str = strlen(str);
		
		int pointer = 0;
		for(int k = 0; k < len_str && pointer < len_key; k++){
			if(str[k] == key[pointer]){
				pointer++;
			}
		}
		
		if(pointer == len_key){
			if(len_str < min){
				min = len_str;
				idx = i;
			}
		}
	}
	
	printf("%d\n", idx);
	return 0;
}