/C06019 - Địa chỉ EMAIL PTIT

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <math.h>
#include <ctype.h>


int main() {
	char s[100];
	gets(s);

	const char* delim = " ";
	char* token = strtok(s, delim);

	while (token != NULL) {
		for (int i = 0; i < strlen(token); i++) {
			token[i] = tolower(token[i]);
		}

		char c[100];
		strcpy(c, token);

		token = strtok(NULL, delim);

		if (token != NULL) printf("%c", c[0]);
		else printf("%s@ptit.edu.vn", c);
	}

	return 0;
}