import java.util.Scanner;
import java.io.*;

public class Main{
    public static void main(String args[]){
        Scanner scan_A = new Scanner(System.in);
        int  str_A = scan_A.nextInt();

       
        int str_B = scan_A.nextInt();

        
        int str_C = scan_A.nextInt();

        int ans;
        int E = str_A - str_B;
        if(E >str_C ){
            ans = 0;
        }else{
           
            ans = str_C -E;
        }
       
               
        System.out.println(ans);
    }

}
/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