unittest
{
	assert( [ "ant", "obe", "rec" ].parse.expand.solve == "abc" );
	assert( [ "edu", "cat", "ion" ].parse.expand.solve == "ean" );
}



import std.conv;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

void main()
{
	stdin.byLineCopy.parse.expand.solve.writeln;
}

auto parse( Range )( Range input )
if( isInputRange!Range && is( ElementType!Range == string ) )
{
	auto css = new string[ 3 ];
	foreach( ref cs; css )
	{
		cs = input.front.strip;
		input.popFront;
	}
	return tuple( css );
}

auto solve( string[] css )
{
	auto s = "";
	foreach( i, cs; css )
	{
		s ~= cs[ i ];
	}
	
	return s;
}
