import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        
        BigDecimal probability = BigDecimal.valueOf(0.5F);
        
        Scanner s = new Scanner(System.in);
        BigDecimal a = s.nextBigDecimal();
        BigDecimal b = s.nextBigDecimal();
        BigDecimal t = s.nextBigDecimal();
        
        BigDecimal resultPart1 = a.multiply(probability).multiply(t);
        BigDecimal resultPart2 = b.multiply(probability).multiply(t);
        BigDecimal result = resultPart1.add(resultPart2);
        
        result = result.remainder(BigDecimal.valueOf(10^9 + 3));
        
        System.out.println(result.intValue());
        
        
        
        
    }
}