import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Akash
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    }

    static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    }

    static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) ATransfer solver = new ATransfer(); solver new ATransfer() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    } ATransfer public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        } solve {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        } int a = in.nextInt() a in.nextInt() in.nextInt in b = in.nextInt() b in.nextInt() in.nextInt in c = in.nextInt(); c in.nextInt() in.nextInt in int available = a - b; available a - b a b int ans = 0; ans 0 if (available >= c)
                ans = c;
            else
                ans = available; available >= c available c ans = c ans c ans = available ans available out.println(c - ans) out.println out c - ans c ans int testNumber testNumber Scanner in in PrintWriter out out public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    }

    static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    }

    static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author Akash
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ATransfer solver = new ATransfer();
        solver.solve(1, in, out);
        out.close();
    }

    static class ATransfer {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int available = a - b;
            int ans = 0;
            if (available >= c)
                ans = c;
            else
                ans = available;
            out.println(c - ans);
        }

    }
}

