s = list(map(int, input().split()))
year = int(s[0])
count = int(s[1])
s = set()
for i in range(count):
    a = input().split()
    first_day = int(a[0])
    dlit = int(a[1])
    s |= set([i for i in range(first_day, year + 1, dlit)])
s_1 = []
for i in s:
    if (i % 7 != 0) & ((i + 1) % 7 != 0):
        s_1.append(i)
print(len(s_1))