import java.util.Scanner;
import java.util.Arrays;

public class Main{
    public static void main(String[]args){
     Scanner sc = new Scanner(System.in);
     int a = sc.nextInt();
     int b = sc.nextInt();int c = sc.nextInt();
     int ans = 0;
     int temp = a - b;
     ans = c - temp;
     if(ans <= 0){
         System.out.println(0);
     }
     else{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