#include<stdio.h>
int main()
{
	char s[5000006];
	scanf("%s", s);
	int i;
	char c = s[0];
	printf("%c", c);
	for (i = 1; s[i] != '\0'; i++)
	{
		if (c == s[i])
			continue;
		c = s[i];
		printf("%c", c);
	}
	printf("\n");
	return 0;
}