import java.util.Scanner;

class Main{
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		
		int num1 = scan.nextInt();
		int num2 = scan.nextInt();
		int num3 = scan.nextInt();
		
		int num4 = num1-num2;
		int ans = num3-num4;
		
		if(ans<0){
			ans = 0;
		}
		
		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