H,W,N = map(int, input().split())
ans = 1

c = [list(map(int, input().split())) for _ in range(H)]

ran = []
for i in range(H):
    for j in range(W-1):
        a = c[i][j]
        b = c[i][j+1]
        if(a!=b):
            if(a<b):
                a,b = b,a
            r = [a,b]
            ran.append(r)

for i in range(H-1):
    for j in range(W):
        a = c[i][j]
        b = c[i+1][j]
        if(a!=b):
            if(a<b):
                a,b = b,a
            r = [a,b]
            ran.append(r)

ran.sort()
mx = 0
for r in ran:
    if(r[1]>=mx):
        mx = r[0]
        ans += 1

print(ans)