Jamie loves sleeping. One day, he decides that he needs to wake up at exactly hh: mm. However, he hates waking up, so he wants to make waking up less painful by setting the alarm at a lucky time. He will then press the snooze button every x minutes until hh: mm is reached, and only then he will wake up. He wants to know what is the smallest number of times he needs to press the snooze button.

A time is considered lucky if it contains a digit '7'. For example, 13: 07 and 17: 27 are lucky, while 00: 48 and 21: 34 are not lucky.

Note that it is not necessary that the time set for the alarm and the wake-up time are on the same day. It is guaranteed that there is a lucky time Jamie can set so that he can wake at hh: mm.

Formally, find the smallest possible non-negative integer y such that the time representation of the time x·y minutes before hh: mm contains the digit '7'.

Jamie uses 24-hours clock, so after 23: 59 comes 00: 00.

Input

The first line contains a single integer x (1 ≤ x ≤ 60).

The second line contains two two-digit integers, hh and mm (00 ≤ hh ≤ 23, 00 ≤ mm ≤ 59).

Output

Print the minimum number of times he needs to press the button.

Examples

Input

3
11 23


Output

2


Input

5
01 07


Output

0

Note

In the first sample, Jamie needs to wake up at 11:23. So, he can set his alarm at 11:17. He would press the snooze button when the alarm rings at 11:17 and at 11:20.

In the second sample, Jamie can set his alarm at exactly at 01:07 which is lucky.

        import java.io.BufferedReader;
        import java.io.BufferedWriter;
        import java.io.IOException;
        import java.io.InputStream;
        import java.io.InputStreamReader;
        import java.io.OutputStream;
        import java.io.OutputStreamWriter;
        import java.io.PrintWriter;
        import java.io.Writer;
        import java.util.ArrayList;
        import java.util.Arrays;
        import java.util.Comparator;
        import java.util.StringTokenizer;


        public class Main {

            public static void main(String[] args) {
                InputStream inputStream = System.in;
                OutputStream outputStream = System.out;
                InputReader  in = new InputReader (inputStream);
                PrintWriter out = new PrintWriter(outputStream);
                Main ob = new Main();
                ob.solve(in, out);
                out.close();
                System.exit(0);
            }
            
            /*
                <---------------------------------------------------------------->
            */
            
            void solve(InputReader in, PrintWriter out){
                int x = in.nextInt();
                int h = in.nextInt();
                int m = in.nextInt();
                int count = 0;
                while((h%10!=7 && h/10!=7) && (m%10!=7 && m/10!=7)){
                    count++;
                    m-=x;
                    if(m<0){
                        h--;
                        m=60- (-1*m);
                    }
                    if(h<0) h=23;
                }
                out.println(count);
            }  
            
            /*
                <---------------------------------------------------------------->
            */
            static class InputReader {
                public BufferedReader reader;
                public StringTokenizer tokenizer;
                public InputReader(InputStream stream) {
                    reader = new BufferedReader(new InputStreamReader(stream), 32768);
                    tokenizer = null;
                }

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

                public int nextInt() {
                    return Integer.parseInt(next());
                }

                public long nextLong() {
                    return Long.parseLong(next());
                }

                public double nextDouble() {
                    return Double.parseDouble(next());
                }

                public String nextLine() {
                    String str = "";
                    try {
                        str = reader.readLine();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                    return str;
                }
            }
        }
