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

int main(){
  char S[5000010];
  fscanf(stdin,"%5000010s",S);
  char a=S[0];
  printf("%c",S[0]);
  char *t=S;
  while(*t!='\0'){
    if(*t!=a)printf("%c",*t);
    a=*t;
    t++;
  }
  printf("\n");
  return 0;
}