#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<string>

std::string md5( const std::string &s )
{
	std::string cmd = "echo -n "+s+"| md5sum";
	FILE *fp = popen( cmd.c_str(), "r" );

	char buf[50];
	fscanf( fp, "%s", buf );
	fclose(fp);

	return buf;
}

int main()
{
	std::string s;
	std::cin >> s;

	std::cout << md5(md5(s)) << std::endl;

	return 0;
}