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

void main(void) {
	char str[500010] = "a";
	scanf("%s",str);
	int i = 0;
	char checkChar = str[0];
	printf("%c",str[0]);
	while(i < (int)strlen(str)){
		if(str[i] != checkChar){
			printf("%c",str[i]);
		}
		checkChar = str[i];
		i++;
	}
}