import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner scan = new Scanner(System.in);

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

        int add = c;
        if(a > b) add = c - (a - b);
        if(add < 0) add = 0;

        System.out.print(add);

        scan.close();
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz