#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();

char wbuf[1<<28];

main(){
	char*rp=mmap(0l,1l<<28,1,2,0,0ll);
	char*wp=wbuf;
	int p=0,c;
	while(c=*rp++,c>=64){
		if(p!=c){
			*wp++=p=c;
		}
	}
	write(1,wbuf,wp-wbuf);
	_exit(0);
}