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

char buf[1<<16];

int main(){
	read(0,buf,1<<16);
	char*rp=buf;
	char*wp=buf;
	long f=0;
	long c;
	while(*rp++!='\n'){
	}
	while(c=*rp++){
		if(c=='\n'){
			if(!f){
				*wp++='0';
			}
			*wp++=c;
			f=0;
		}
		if(c>'0'){
			f=1;
		}
		if(f){
			*wp++=c;
		}
	}
	write(1,buf,wp-buf);
	_exit(0);
}