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

char*mmap();
char wbuf[1<<20];

main(){
	char*rp=mmap(0l,1l<<28,1,2,0,0ll);
	char*wp=wbuf;
	while(*rp++!=10);
	char*a=rp;
	while(*rp++!=10);
	char*b=rp;

	while(*b){
		if(*a==*b){
			++a;
			++b;
		}else{
			*wp++=*a++;
		}
	}
	write(1,wbuf,wp-wbuf);
	_exit(0);
}