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.

// AUTHOR : MAYANK SUNAL
import java.io.*;
import java.util.*;
import java.math.*;

public class Main {
	int p;
	int s;

	Main(int p, int s) {
		this.p = p;
		this.s = s;
	}

	static final Random random = new Random();
	static PrintWriter out = new PrintWriter((System.out));
	static Reader sc = new Reader();

	public static void main(String args[]) throws IOException {
//		int t = sc.nextInt();
//		while (t-- > 0) {
//        	CODE START FROM HERE 
		int x = sc.nextInt();
		int h = sc.nextInt();
		int m = sc.nextInt();
		String hh = String.valueOf(h);
		String mm = String.valueOf(m);
		if (hh.contains("7") || mm.contains("7"))
			System.out.println(0);
		else {
			int time = 60 * h + m;
			if (time == 0)
				time = 1440;
			int dh = 0;
			int dm = 0;
			int count = 0;
			while (true) {
				time -= x;
				if (time <= 0)
					time =1440 + time;
				++count;
				dh = time / 60;
				dm = time % 60;
				hh = String.valueOf(dh);
				mm = String.valueOf(dm);
				if (hh.contains("7") || mm.contains("7"))
					break;
			}
			System.out.println(count);

		}

	}

//	}

// }
// Fast Input Output
	static class Reader {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer("");

		public String next() {
			while (!st.hasMoreTokens()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			return st.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() {
			try {
				return br.readLine();
			} catch (Exception e) {
				e.printStackTrace();
			}
			return null;
		}

		public boolean hasNext() {
			String next = null;
			try {
				next = br.readLine();
			} catch (Exception e) {
			}
			if (next == null) {
				return false;
			}
			st = new StringTokenizer(next);
			return true;
		}

	}

	// EFFICIENT SORTING Ascending
	static void ruffleSortAsc(Integer[] a) {
		int n = a.length; // shuffle, then sort
		for (int i = 0; i < n; i++) {
			int oi = random.nextInt(n), temp = a[oi];
			a[oi] = a[i];
			a[i] = temp;
		}
		Arrays.sort(a);
	}

//	EFFICIENT SORTING Descending
	static void ruffleSortDesc(Integer[] a) {
		int n = a.length; // shuffle, then sort
		for (int i = 0; i < n; i++) {
			int oi = random.nextInt(n), temp = a[oi];
			a[oi] = a[i];
			a[i] = temp;
		}
		Arrays.sort(a, Collections.reverseOrder());
	}

	// Array Sum
	static long sum(Integer[] arr) {
		long sum = 0;
		for (int i : arr)
			sum += i;
		return sum;
	}

	// ArrayList Sum
	static long sumal(ArrayList<Integer> al) {
		long sum = 0;
		for (int i : al)
			sum += i;
		return sum;
	}

	// swap array elements
	static void swap(int arr1[], int arr2[], int i, int j) {
		int temp = arr1[i];
		arr1[i] = arr2[j];
		arr2[j] = temp;
	}

	// reading array value;
	static void read(Integer[] arr) {
		for (int i = 0; i < arr.length; i++)
			arr[i] = sc.nextInt();
		return;
	}

//    reading arraylistValue

	static void readal(List<Integer> l, int n) {
		for (int i = 0; i < n; i++)
			l.add(sc.nextInt());
		return;
	}

	// check for even odd
	static boolean isEven(long n) {
		return ((n & 1) != 1);
	}

	// max in a array
	static int max(Integer[] arr) {
		int max = Integer.MIN_VALUE;
		for (int i = 0; i < arr.length; i++)
			if (max < arr[i])
				max = arr[i];
		return max;
	}

//  print array
	static void printarr(Integer arr[]) {
		for (int i : arr)
			System.out.println(i);
	}

// ceil of two elements
	static int ceil(long l, int b) {
		return (int) Math.ceil(((double) l / (double) b));
	}

// floor of two elements
	static int floor(int a, int b) {
		return (int) Math.floor(((double) a / (double) b));
	}
}