Vasily the Bear loves beautiful strings. String s is beautiful if it meets the following criteria: 

  1. String s only consists of characters 0 and 1, at that character 0 must occur in string s exactly n times, and character 1 must occur exactly m times. 
  2. We can obtain character g from string s with some (possibly, zero) number of modifications. The character g equals either zero or one. 



A modification of string with length at least two is the following operation: we replace two last characters from the string by exactly one other character. This character equals one if it replaces two zeros, otherwise it equals zero. For example, one modification transforms string "01010" into string "0100", two modifications transform it to "011". It is forbidden to modify a string with length less than two.

Help the Bear, count the number of beautiful strings. As the number of beautiful strings can be rather large, print the remainder after dividing the number by 1000000007 (109 + 7). 

Input

The first line of the input contains three space-separated integers n, m, g (0 ≤ n, m ≤ 105, n + m ≥ 1, 0 ≤ g ≤ 1).

Output

Print a single integer — the answer to the problem modulo 1000000007 (109 + 7).

Examples

Input

1 1 0


Output

2


Input

2 2 0


Output

4


Input

1 1 1


Output

0

Note

In the first sample the beautiful strings are: "01", "10".

In the second sample the beautiful strings are: "0011", "1001", "1010", "1100".

In the third sample there are no beautiful strings.
import java.io.OutputStreamWriter;
import java.io.BufferedWriter;
import java.util.Locale;
import java.io.OutputStream;
import java.util.RandomAccess;
import java.io.PrintWriter;
import java.util.AbstractList;
import java.io.Writer;
import java.util.List;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.math.BigInteger;
import java.util.Collections;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Jacob Jiang
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);
		TaskD solver = new TaskD();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskD {
    private static final long MOD = (long) (1e9 + 7);

    long[] factorial = NumberUtils.generateFactorial(250000, MOD);
    long[] reverseFactorial = NumberUtils.generateReverseFactorials(250000, MOD);

    public void solve(int testNumber, InputReader in, OutputWriter out) {
        int n = in.nextInt();
        int m = in.nextInt();
        int g = in.nextInt();
        long answer = 0;
        while (n + m > 0) {
            if (n + m == 1) {
                if ((n == 1 && g == 0) || (m == 1 && g == 1)) {
                    answer++;
                    if (answer >= MOD)
                        answer -= MOD;
                }
                break;
            }
            if (g == 1) {
                if (n == 0) {
                    break;
                }
                n--;
                g = 0;
            } else {
                if (m >= 1) {
                    answer += factorial[n + m - 1] * reverseFactorial[m - 1] % MOD *
                            reverseFactorial[n] % MOD;
                    if (answer >= MOD)
                        answer -= MOD;
                }
                if (n >= 1) {
                    n--;
                    g = 1;
                } else {
                    break;
                }
            }
        }
        out.println(answer);
    }
}

class NumberUtils {

    public static long[] generateFactorial(int count, long module) {
        long[] result = new long[count + 1];
        if (module == -1) {
            if (count != 0)
                result[0] = 1;
            for (int i = 1; i <= count; i++)
                result[i] = result[i - 1] * i;
        } else {
            if (count != 0)
                result[0] = 1 % module;
            for (int i = 1; i <= count; i++)
                result[i] = (result[i - 1] * i) % module;
        }
        return result;
    }

    public static long[] generateReverse(int count, long module) {
        if (count < 0)
            throw new IllegalArgumentException();
        long[] result = new long[count + 1];
        if (count > 0)
            result[1] = 1;
        for (int i = 2; i <= count; i++)
            result[i] = (module - module / i * result[((int) (module % i))] % module) % module;
        return result;
    }

    public static long[] generateReverseFactorials(int count, long module) {
        if (count < 0)
            throw new IllegalArgumentException();
        long[] result = generateReverse(count, module);
        result[0] = 1;
        for (int i = 1; i <= count; i++)
            result[i] = result[i] * result[i - 1] % module;
        return result;
    }
}

class InputReader {

    private InputStream stream;
    private byte[] buf = new byte[1 << 16];
    private int curChar;
    private int numChars;

    public InputReader(InputStream stream) {
        this.stream = stream;
    }

    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 & 15;
            c = read();
        } while (!isSpaceChar(c));
        return res * sgn;
    }

    public static boolean isSpaceChar(int c) {
        return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
    }

    }

class OutputWriter {
    private PrintWriter writer;

    public OutputWriter(OutputStream stream) {
        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(stream)));
    }

    public OutputWriter(Writer writer) {
        this.writer = new PrintWriter(writer);
    }

    public void println(long x) {
        writer.println(x);
    }

    public void close() {
        writer.close();
    }

    }

