unittest
{
	assert( [ "5", "error", "2" ].parse.expand.solve == "*rr*r" );
	assert( [ "6", "eleven", "5" ].parse.expand.solve == "e*e*e*" );
	assert( [ "9", "education", "7" ].parse.expand.solve == "******i**" );
}



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

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

auto parse( Range )( Range input )
if( isInputRange!Range && is( ElementType!Range == string ) )
{
	auto n = input.front.to!( long );
	input.popFront;
	auto s = input.front;
	input.popFront;
	auto k = input.front.to!( long );
	return tuple( n, s, k );
}

auto solve( long n, string s, long k )
{
	auto ans = s.dup;
	foreach( ref c; ans )
	{
		if( s[ k - 1 ] != c ) c = '*';
	}
	return ans;
}
