import java.util.*;
public class Main {
    public static void main (String[]args){
        // 標準入力
        Scanner sc = new Scanner(System.in);
        
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();

        sc.close();

        int full = A - B;
        int rest = C - full;

        if (rest >= 0){
            System.out.println(rest);
        } else{
            System.out.println(0);
        }
        

    }   
}
/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