import java.util.*;

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 res = A - B;
    	if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	}

        System.out.println(res);
    }
} import java.util.*; util.* java 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 res = A - B;
    	if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	}

        System.out.println(res);
    }
} 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 res = A - B;
    	if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	}

        System.out.println(res);
    } main {
        Scanner sc = new Scanner(System.in);
        int A = sc.nextInt();
        int B = sc.nextInt();
        int C = sc.nextInt();

        int res = A - B;
    	if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	}

        System.out.println(res);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int A = sc.nextInt(); A sc.nextInt() sc.nextInt sc int B = sc.nextInt(); B sc.nextInt() sc.nextInt sc int C = sc.nextInt(); C sc.nextInt() sc.nextInt sc int res = A - B; res A - B A B if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	} res >= C res C {
    		res = 0;
    	} res = 0 res 0 {
    		res = C - res;
    	} res = C - res res C - res C res System.out.println(res) System.out.println System.out System System.out res String[] args args
import java.util.*;

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 res = A - B;
    	if (res >= C) {
    		res = 0;
    	} else {
    		res = C - res;
    	}

        System.out.println(res);
    }
}