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

int main()
{
	int y,i = 0;
	char x[20] = "";
	char sum[200] = "";
	scanf("%d", &y);
	
	while(i < y){
		scanf("%s", x);
		strcat(sum,x);
		i++;
	}
	printf("%s", sum);
	
	return (0);
}