import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    }
}

class Interval {
    int start;
    int end;

    public int getStart() {
        return start;
    }

    public int getEnd() {
        return end;
    }

    public Interval(int start, int end) {
        this.start = start;
        this.end = end;
    }

    @Override
    public String toString() {
        return
                "start=" + start +
                ", end=" + end +
                '}';
    }
}


class InputReader extends BufferedReader {
    StringTokenizer tokenizer;

    public InputReader(InputStream inputStream) {
        super(new InputStreamReader(inputStream), 32768);
    }

    public InputReader(String filename) {
        super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return tokenizer.nextToken();
    }

    public Integer nextInt(){
        return Integer.valueOf(next());
    }
    public Long nextLong() {
        return  Long.valueOf(next());
    }
    public Double nextDouble() {
        return Double.valueOf(next());
    }
    static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        }

        public OutputWriter(Writer writer) {
            super(writer);
        }

        public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        }

        public void close() {
            super.close();
        }
    }
} import java.io.*; io.* java import java.math.BigInteger; BigInteger java.math import java.util.*; util.* java public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    }
} Main public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out InputReader in = new InputReader(inputStream); in new InputReader(inputStream) InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream); out new InputReader.OutputWriter(outputStream) int x = in.nextInt(); x in.nextInt() in.nextInt in long ans = 0; ans 0 int hundred = x/500; hundred x/500 x 500 x-=hundred*500 x hundred*500 hundred 500 int five = x/5; five x/5 x 5 out.println(hundred * 1000 + five * 5) out.println out hundred * 1000 + five * 5 hundred * 1000 hundred 1000 five * 5 five 5 out.flush() out.flush out String[] args args class Interval {
    int start;
    int end;

    public int getStart() {
        return start;
    }

    public int getEnd() {
        return end;
    }

    public Interval(int start, int end) {
        this.start = start;
        this.end = end;
    }

    @Override
    public String toString() {
        return
                "start=" + start +
                ", end=" + end +
                '}';
    }
} Interval int start; start int end; end public int getStart() {
        return start;
    } getStart {
        return start;
    } return start; start public int getEnd() {
        return end;
    } getEnd {
        return end;
    } return end; end public Interval(int start, int end) {
        this.start = start;
        this.end = end;
    } Interval {
        this.start = start;
        this.end = end;
    } this.start = start this.start this this.start start this.end = end this.end this this.end end int start start int end end @Override
    public String toString() {
        return
                "start=" + start +
                ", end=" + end +
                '}';
    } toString {
        return
                "start=" + start +
                ", end=" + end +
                '}';
    } return
                "start=" + start +
                ", end=" + end +
                '}'; "start=" + start +
                ", end=" + end +
                '}' end ", end=" "start=" + start +
                ", end=" + end +
                '}' "start=" start ", end=" end '}' class InputReader extends BufferedReader {
    StringTokenizer tokenizer;

    public InputReader(InputStream inputStream) {
        super(new InputStreamReader(inputStream), 32768);
    }

    public InputReader(String filename) {
        super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return tokenizer.nextToken();
    }

    public Integer nextInt(){
        return Integer.valueOf(next());
    }
    public Long nextLong() {
        return  Long.valueOf(next());
    }
    public Double nextDouble() {
        return Double.valueOf(next());
    }
    static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        }

        public OutputWriter(Writer writer) {
            super(writer);
        }

        public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        }

        public void close() {
            super.close();
        }
    }
} InputReader StringTokenizer tokenizer; tokenizer public InputReader(InputStream inputStream) {
        super(new InputStreamReader(inputStream), 32768);
    } InputReader {
        super(new InputStreamReader(inputStream), 32768);
    } super(new InputStreamReader(inputStream), 32768) super new InputStreamReader(inputStream) 32768 InputStream inputStream inputStream public InputReader(String filename) {
        super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
    } InputReader {
        super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
    } super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename))) super new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)) String filename filename public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return tokenizer.nextToken();
    } next {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return tokenizer.nextToken();
    } while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        } try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            } catch (IOException e) {
                throw new RuntimeException();
            } IOException e {
                throw new RuntimeException();
            } throw new RuntimeException(); new RuntimeException() {
                tokenizer = new StringTokenizer(readLine());
            } tokenizer = new StringTokenizer(readLine()) tokenizer new StringTokenizer(readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public Integer nextInt(){
        return Integer.valueOf(next());
    } nextInt {
        return Integer.valueOf(next());
    } return Integer.valueOf(next()); Integer.valueOf(next()) Integer.valueOf Integer next() next public Long nextLong() {
        return  Long.valueOf(next());
    } nextLong {
        return  Long.valueOf(next());
    } return  Long.valueOf(next()); Long.valueOf(next()) Long.valueOf Long next() next public Double nextDouble() {
        return Double.valueOf(next());
    } nextDouble {
        return Double.valueOf(next());
    } return Double.valueOf(next()); Double.valueOf(next()) Double.valueOf Double next() next static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        }

        public OutputWriter(Writer writer) {
            super(writer);
        }

        public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        }

        public void close() {
            super.close();
        }
    } OutputWriter public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        } OutputWriter {
            super(outputStream);
        } super(outputStream) super outputStream OutputStream outputStream outputStream public OutputWriter(Writer writer) {
            super(writer);
        } OutputWriter {
            super(writer);
        } super(writer) super writer Writer writer writer public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        } OutputWriter {
            super(filename);
        } super(filename) super filename String filename filename public void close() {
            super.close();
        } close {
            super.close();
        } super.close() super.close super PrintWriter BufferedReader public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    }
} public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    }
} Main
import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        InputReader.OutputWriter out = new InputReader.OutputWriter(outputStream);

        int x = in.nextInt();
        long ans = 0;
        int hundred = x/500;
        x-=hundred*500;
        int five = x/5;
        out.println(hundred * 1000 + five * 5);

        out.flush();
    }
}

class Interval {
    int start;
    int end;

    public int getStart() {
        return start;
    }

    public int getEnd() {
        return end;
    }

    public Interval(int start, int end) {
        this.start = start;
        this.end = end;
    }

    @Override
    public String toString() {
        return
                "start=" + start +
                ", end=" + end +
                '}';
    }
}


class InputReader extends BufferedReader {
    StringTokenizer tokenizer;

    public InputReader(InputStream inputStream) {
        super(new InputStreamReader(inputStream), 32768);
    }

    public InputReader(String filename) {
        super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
    }

    public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(readLine());
            } catch (IOException e) {
                throw new RuntimeException();
            }
        }
        return tokenizer.nextToken();
    }

    public Integer nextInt(){
        return Integer.valueOf(next());
    }
    public Long nextLong() {
        return  Long.valueOf(next());
    }
    public Double nextDouble() {
        return Double.valueOf(next());
    }
    static class OutputWriter extends PrintWriter {
        public OutputWriter(OutputStream outputStream) {
            super(outputStream);
        }

        public OutputWriter(Writer writer) {
            super(writer);
        }

        public OutputWriter(String filename) throws FileNotFoundException {
            super(filename);
        }

        public void close() {
            super.close();
        }
    }
}
