n, k = map(int, input().split())
used = [0 for i in range(n)]
for i in range(k):
    a, b = map(int, input().split())
    a -= 1
    for j in range(a, n, b):
        used[j] = 1
cnt = 0
for i in range(n):
    if(used[i] and i % 7 < 5):
       cnt += 1
print(cnt)