#include <stdio.h>

#define WRAP 7000

int main(void)
{
	int c, i = 0, saved_values[WRAP];
	while ( i < WRAP ) saved_values[i++] = 0;
	i = 0;
	while ( ( c = getchar() ) != EOF ) {
		saved_values[i] = ( saved_values[i] + c ) * 2 / 3;
		putchar( saved_values[i++] );
		i %= WRAP;
	}
}