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.
'''input
1 2 3
4 5
6 7 8
45 9
'''

import sys
pow2 = pow              # for modular expo pow2(base, n, mod)
from math import *
from time import time
from collections import defaultdict
from bisect import bisect_right, bisect_left
from string import ascii_lowercase as lcs
from string import ascii_uppercase as ucs
from fractions import Fraction, gcd
from decimal import Decimal, getcontext
from itertools import product, permutations, combinations
#getcontext().prec = 500
#sys.setrecursionlimit(30000)

# What doesn't challenge you, makes you weaker.

mod = 10**9 + 7
INF = sys.maxint

raw_input = lambda: sys.stdin.readline().rstrip()
die = lambda : exit(0)
flush= lambda : sys.stdout.flush()

r_s = lambda: raw_input().strip()                   #read str
r_ss = lambda: raw_input().split()          #read stringss
r_i = lambda: int(raw_input())              #read int
r_is = lambda: map(int, raw_input().split())#read ints
r_f = lambda: float(raw_input())            #read float
r_fs = lambda: map(Decimal, raw_input().split()) #read floats

# For effieciently taking lots of queries with each query in a separate line
# having integer values separated by space. A 2d list is made with each row
# corresponding to line. Each row is a list with all the values.
# Use this for fast I/O by taking all input in one go.
r_qs = lambda: map(lambda s:map(int, s.split(' ')), sys.stdin.readlines())

'''-------------------------------------------------------------------'''

# Call it as dbg(varName=varName)
def dbg(**kwargs):
    print "Value of '" + kwargs.keys()[0] + "' is", kwargs[kwargs.keys()[0]]


def main():
    x= r_i()
    hh, mm = r_is()
    ans = 10000000
    cnt = 0
    while('7' not in (str(hh)+str(mm))):
        if mm>=x:
            mm-=x
        elif hh>0:
            hh-=1
            mm = 60+mm-x
        else:
            hh = 23
            mm = 60+mm-x
        cnt += 1
    print cnt

if __name__ == '__main__':
    local = True
    # local = False
    if local:
        try:
            sys.stdin = open('input.txt')
            print 'Running at local.'
            for i in range(r_i()):
                main()
        except IOError:
            main()
    else:
        main()


