Problem: Dreamoon is standing at the position 0 on a number line. Drazil is sending a list of commands through Wi-Fi to Dreamoon's smartphone and Dreamoon follows them.

Each command is one of the following two types: 

  1. Go 1 unit towards the positive direction, denoted as '+'
  2. Go 1 unit towards the negative direction, denoted as '-'



But the Wi-Fi condition is so poor that Dreamoon's smartphone reports some of the commands can't be recognized and Dreamoon knows that some of them might even be wrong though successfully recognized. Dreamoon decides to follow every recognized command and toss a fair coin to decide those unrecognized ones (that means, he moves to the 1 unit to the negative or positive direction with the same probability 0.5). 

You are given an original list of commands sent by Drazil and list received by Dreamoon. What is the probability that Dreamoon ends in the position originally supposed to be final by Drazil's commands?

Input

The first line contains a string s1 — the commands Drazil sends to Dreamoon, this string consists of only the characters in the set {'+', '-'}. 

The second line contains a string s2 — the commands Dreamoon's smartphone recognizes, this string consists of only the characters in the set {'+', '-', '?'}. '?' denotes an unrecognized command.

Lengths of two strings are equal and do not exceed 10.

Output

Output a single real number corresponding to the probability. The answer will be considered correct if its relative or absolute error doesn't exceed 10 - 9.

Examples

Input

++-+-
+-+-+


Output

1.000000000000


Input

+-+-
+-??


Output

0.500000000000


Input

+++
??-


Output

0.000000000000

Note

For the first sample, both s1 and s2 will lead Dreamoon to finish at the same position  + 1. 

For the second sample, s1 will lead Dreamoon to finish at position 0, while there are four possibilites for s2: {"+-++", "+-+-", "+--+", "+---"} with ending position {+2, 0, 0, -2} respectively. So there are 2 correct cases out of 4, so the probability of finishing at the correct position is 0.5. 

For the third sample, s2 could only lead us to finish at positions {+1, -1, -3}, so the probability to finish at the correct position  + 3 is 0.

Solution (in JAVA):

Solution:
    import java.util.*;
    import java.io.*;
     
    public class Main {
	static InputReader scn = new InputReader(System.in);
	static OutputWriter out = new OutputWriter(System.out);
	public static void main(String[] HastaLaVistaLa) {
		// Running Number Of TestCases (t)
		int t = 1;
		while(t-- > 0)
			solve();
		out.close();
	}

	public static void dummy(){
		int n = scn.nextInt();
		out.println(n);
	}

	static int[] dp;
	static int total;
	static int favourable;
	public static void solve() {
		// Main Solution (AC)	
		char[] draz = scn.next().toCharArray();
		char[] door = scn.next().toCharArray();
		int n = door.length;
		total = 0;
		favourable = 0;
		int pos = 0;
		for(char ch : door) if(ch == '?') total++;
		for(int i = 0; i < n; i++) {
			if(draz[i] == '+') pos++;
			else pos--;
		}
		int ans = DP(door, 0, pos, n, 0);
		total = (int) Math.pow(2, total);
		if(total == 0) out.println(1.0d);
		else out.println((double) favourable / (double) total);

	}

	public static int DP(char[] door, int idx, int pos, int n, int ans1) {

		if(idx == n && ans1 == pos) favourable++;	
		if(idx == n) return 0;
		if(door[idx] == '+') return DP(door, idx + 1, pos, n, ans1 + 1);
		else if(door[idx] == '-') return DP(door, idx + 1, pos, n, ans1 - 1);
		else {
			int v1 = DP(door, idx + 1, pos, n, ans1 + 1);
			int v2 = DP(door, idx + 1, pos, n, ans1 - 1);
			return v1;
		}
	}

	// Number of Divisor for Range [l, r]
	public static int[] NumberOFDivisors(int l, int r) {
		int[] arr = new int[l - r + 1];
		for(int i = l; i <= r; i++) {
			for(int j = i; j <= r; j += i)
				arr[j]++;
		}
		return arr;
	}

	public static int LowerBound(long a[], long x) { // x is the target value or key

		  int l = -1,r = a.length;
		  while(l + 1 < r) {

		    int m = (l + r) >>> 1;
		    if(a[m] >= x) r = m;
		    else l = m;

		  }
		  return r;
	}

	static boolean[] prime;
	public static void sieveOfEratosthenes(int n) {
        	prime = new boolean[n+1];
	        for(int i=0;i<n;i++)
	            prime[i] = true;
	          
	        for(int p = 2; p*p <=n; p++) {

	            if(prime[p] == true) {

	                for(int i = p*p; i <= n; i += p)
	                    prime[i] = false;
	            }
	        }
    	}

	public static long binpow(long n, long m, long mod) {
	        long res = 1;
	        while (m > 0) {
	            if (m % 2 == 1) {
	                res *= n;
	                res %= mod;
	                m--;
	            }
	            n *= n;
	            n %= mod;
	            m /= 2;
	        }
	        return res;
    	}

	public static int UpperBound(long a[], long x) {// x is the key or target value

		    int l = -1,r = a.length;

		    while(l + 1 < r) {

		       int m = (l + r) >>> 1;
		       if(a[m] <= x) l = m;
		       else r = m;

		    }
		    return l + 1;
	}

    	public static long lcm(long a, long b) {
		return (a * b) / gcd(a, b);
	}
     
	public static long gcd(long a, long b) {
		if (a == 0)
			return b;
		return gcd(b % a, a);
	}
	public static HashMap<Integer, Integer> CountFrequencies(int[] arr) {
     
		HashMap<Integer, Integer> map = new HashMap<>();
		for (int i : arr) {
			if (map.containsKey(i)) map.put(i, map.get(i) + 1);
			else map.put(i, 1);
		}
		return map;
	}

	public static void sort(int[] arr) {
		Random rand = new Random();
		int n = arr.length;
		for(int i = 0; i<n; i++) {
			swap(arr, i, rand.nextInt(n));
		}
		Arrays.sort(arr);
	}

	public static void swap(int[] arr, int i, int j) {
		if(i!=j) {
			arr[i] ^= arr[j];
			arr[j] ^= arr[i];
			arr[i] ^= arr[j];
		}
	}
     
	public static void sortbyColumn(int[][] arr, int col) {
		Arrays.sort(arr, new Comparator<int[]>() {
			public int compare(final int[] entry1, final int[] entry2) {
				if (entry1[col] > entry2[col])
					return 1;
				else
					return -1;
			}
		});
	}

	public static void ArraySort2D(int[][] arr, int xy) {
		// xy == 0, for sorting wrt X-Axis
		// xy == 1, for sorting wrt Y-Axis
		Arrays.sort(arr, Comparator.comparingDouble(o -> o[xy]));
	}
	
	public static int binarySearch(int arr[], int l, int r, int x) {
		if (r >= l) {
			int mid = l + (r - l) / 2;
			if (arr[mid] == x)
				return mid;
			if (arr[mid] > x)
				return binarySearch(arr, l, mid - 1, x);
			return binarySearch(arr, mid + 1, r, x);
		}
		return -1;
	}
     
	static class InputReader {
		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar;
		private int numChars;
		private SpaceCharFilter filter;
     
		public InputReader(InputStream stream) {
			this.stream = stream;
		}
     
		public int[] readIntArray(int n) {
			int[] a = new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = scn.nextInt();
			}
			return a;
		}
     			
     		public long[] readLongArray(int n) {
			long[] a = new long[n];
			for (int i = 0; i < n; i++) {
				a[i] = scn.nextLong();
			}
			return a;
		}

		public int read() {
			if (numChars == -1)
				throw new InputMismatchException();
			if (curChar >= numChars) {
				curChar = 0;
				try {
					numChars = stream.read(buf);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (numChars <= 0)
					return -1;
			}
			return buf[curChar++];
		}
     
		public int nextInt() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
     
		public long nextLong() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			int sgn = 1;
			if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
				c = read();
			} while (!isSpaceChar(c));
			return res * sgn;
		}
     
		public String nextLine() {
			int c = read();
			while (isSpaceChar(c))
				c = read();
			StringBuilder res = new StringBuilder();
			do {
				res.appendCodePoint(c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}
     
		public boolean isSpaceChar(int c) {
			if (filter != null)
				return filter.isSpaceChar(c);
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
     
		public String next() {
			return nextLine();
		}
     
		public interface SpaceCharFilter {
			public boolean isSpaceChar(int ch);
		}
	}
     
	static class OutputWriter {
		private final PrintWriter writer;
     
		public OutputWriter(OutputStream outputStream) {
			writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
		}
     
		public OutputWriter(Writer writer) {
			this.writer = new PrintWriter(writer);
		}
     
		public void print(Object... objects) {
			for (int i = 0; i < objects.length; i++) {
				if (i != 0) {
					writer.print(' ');
    //                    writer.print(1);
				}
				writer.print(objects[i]);
			}
		}
     
		public void println(Object... objects) {
			print(objects);
			writer.println();
		}
     
		public void close() {
			writer.close();
		}
	}
}