Percolation

n = input().split()
k = int(n[1])
razm = int(n[0])

graf = []
met = []

for m in range(razm):
    graf.append([])
    met.append([])
    for z in range(razm):
        graf[m].append(1)
        met[m].append(0)

for i in range(k):
    s = input().split()
    graf[int(s[0])][int(s[1])] = 0

for g in range(razm):
    if graf[0][g] == 0:
        h = 0
        j = g
        och = [[h, g]]
        while och != []:
            d = och.pop(0)
            i = d[0]
            j = d[1]
            if i != razm - 1:
                if graf[i + 1][j] == 0 and met[i + 1][j] == 0:
                    och.append([i + 1, j])
                    met[i + 1][j] = 1
            if i != 0:
                if graf[i - 1][j] == 0 and met[i - 1][j] == 0:
                    och.append([i - 1, j])
                    met[i - 1][j] = 1

            if j != razm - 1:
                if graf[i][j + 1] == 0 and met[i][j + 1] == 0:
                    och.append([i, j + 1])
                    met[i][j + 1] = 1

            if j != 0:
                if graf[i][j - 1] == 0 and met[i][j - 1] == 0:
                    och.append([i, j - 1])
                    met[i][j - 1] = 1

s = sum(met[razm-1])

if s == 0:
    print('No')
else:
    print('Yes')