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.util.List;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.ArrayList;
import java.io.BufferedReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.StringTokenizer;
import java.io.InputStream;

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

class TaskD {
    int[] factorials;
    int mod = 1000000007;
    public void solve(int testNumber, Reader in, OutputWriter out) {
        int nulls = in.nextInt();
        int ones = in.nextInt();
        int res = in.nextInt();
        factorials = IntegerUtils.factorials(nulls + ones + 1, mod);
        if(ones == 0) {
            out.println(res == nulls % 2 ? 0 : 1);
            return;
        }
        long answer = 0;

        if(ones == 1) {
            answer += res == nulls % 2 ? 0 : 1;
        }
        for(int firstOne = res; nulls - firstOne >= 0; firstOne += 2) {
            int nullsRemaining = nulls - firstOne;
            int onesRemaining = ones - 1;

            if(nullsRemaining == 0 && onesRemaining == 0)
                continue;


            answer += c(nullsRemaining + onesRemaining, onesRemaining);
            answer %= mod;
        }

        out.println(answer);
    }

    private long c(int n, int k) {
        return factorials[n] * IntegerUtils.modInverse(factorials[k], mod) % mod * IntegerUtils.modInverse(factorials[n - k], mod) % mod;
    }
}

class Reader {
    private BufferedReader reader;
    private StringTokenizer tokenizer;

    public Reader(BufferedReader reader) {
        this.reader = reader;
    }

    public Reader(InputStream stream) {
        this(new BufferedReader(new InputStreamReader(stream)));
    }

    public String nextString() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(readLine());
        }
        return tokenizer.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(nextString());
    }

    private String readLine() {
        try {
            return reader.readLine();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

class OutputWriter extends PrintWriter {

	public OutputWriter(OutputStream out) {
		super(out);
	}

	public OutputWriter(java.io.Writer writer){
		super(writer);
	}

	}

class IntegerUtils {

	public static int[] factorials(int n, int mod){
		int [] fact = new int[n + 1];
		fact[0] = 1;
		for(int i = 1; i <= n; ++i)
			fact[i] = (int) (fact[i - 1] * 1L * i % mod);
		return fact;
	}

	public static long power(long base, long power, long mod) {
		long result = 1 % mod;
		base %= mod;
		while (power > 0) {
			if (power % 2 == 1) {
				result *= base;
				result %= mod;
			}
			base *= base;
			base %= mod;
			power >>= 1;
		}
		return result;
	}

	public static long modInverse(long number, long mod) {
		return power(number, mod - 2, mod);
	}

	}
