import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.math.BigInteger;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
class board
{
static final BigInteger BIGTWO = BigInteger.valueOf(2);
static BigInteger min(BigInteger a, BigInteger b)
{
return a.compareTo(b) < 0 ? a : b;
}
static int Depth(String aString)
{
char [] a = aString.toCharArray();
int depth = 0;
for (char i: a)
if (i == 'U')
--depth;
else if (i == '1' || i == '2')
++depth;
return depth;
}
static BigInteger Coord(String aString)
{
char [] a = aString.toCharArray();
BigInteger coord = BigInteger.ZERO;
for (char i: a)
switch(i)
{
case '1':
coord = coord.multiply(BIGTWO); break;
case '2':
coord = coord.multiply(BIGTWO);
coord = coord.add(BigInteger.ONE); break;
case 'L':
coord = coord.subtract(BigInteger.ONE); break;
case 'R':
coord = coord.add(BigInteger.ONE); break;
case 'U':
coord = coord.divide(BIGTWO);
}
return coord;
}
public static void main(String[] args)
{
InputStream inputStream = System.in;
OutputStream outputStream = System.out;
InputReader in = new InputReader(inputStream);
PrintWriter out = new PrintWriter(outputStream);
String path = in.nextString();
int aDepth = Depth(path);
BigInteger aCoord = Coord(path);
path = in.nextString();
int bDepth = Depth(path);
BigInteger bCoord = Coord(path);
if (aDepth > bDepth)
{
int temp1 = aDepth; aDepth = bDepth; bDepth = temp1;
BigInteger temp2 = aCoord; aCoord = bCoord; bCoord = temp2;
}
int depthSteps = bDepth - aDepth;
bDepth = aDepth;
bCoord = bCoord.shiftLeft(-depthSteps);
BigInteger ans = aCoord.subtract(bCoord).abs().add(BigInteger.valueOf(depthSteps));
while (aDepth-- > 0)
{
depthSteps += 2;
aCoord = aCoord.divide(BIGTWO);
bCoord = bCoord.divide(BIGTWO);
ans = min(ans, aCoord.subtract(bCoord).abs().add(BigInteger.valueOf(depthSteps)));
}
out.println(ans);
out.close();
}
static class InputReader
{
public BufferedReader reader;
public StringTokenizer tokenizer;
public InputReader(InputStream stream)
{
reader = new BufferedReader(new InputStreamReader(stream), 32768);
tokenizer = null;
}
public String nextString()
{
while (tokenizer == null || !tokenizer.hasMoreTokens())
{
try { tokenizer = new StringTokenizer(reader.readLine()); }
catch (IOException e) { throw new RuntimeException(e); }
}
return tokenizer.nextToken();
}
public int nextInt()
{
return Integer.parseInt(nextString());
}
}
}
