unittest
{
	assert( [ "xyz", "abc" ].parse.expand.solve == "xaybzc" );
	assert( [ "atcoderbeginnercontest", "atcoderregularcontest" ].parse.expand.solve == "aattccooddeerrbreeggiunlnaerrccoonntteesstt" );
}



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 o = input.front;
	input.popFront;
	auto e = input.front;
	return tuple( o, e );
}

auto solve( string o, string e )
{
	auto ans = new char[ o.length + e.length ];
	foreach( i, ref c; ans )
	{
		if( i % 2 == 0 ) c = o[ i / 2 ];
		else             c = e[ i / 2 ];
	}
	return ans;
}
