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

#define LEN 20

int main(){

	char** str;
	char* moji;
	int i;
	int n;

	scanf("%d",&n);
	str = (char**)calloc(n,sizeof(char*));
	moji = (char*)calloc(LEN*n+1,sizeof(char));

	for(i=0;i<n;i++){
		str[i] = (char*)calloc(LEN+1,sizeof(char));
		scanf("%s",str[i]);
	}

	strcpy(moji,str[0]);

	for(i=1;i<n;i++){
		strcat(moji,str[i]);
	}

	printf("%s\n",moji);

	return 0;
}