import java.util.Scanner;

public class E05AddAndSubtract {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = scanner.nextInt();

        subtract(add(a,b),c);

    }
    static int add (int a, int b){
        int sum = a + b;
        return sum;
    }

    static void subtract (int a, int b){
        System.out.println(a - b);
    }
}