import sys
input = sys.stdin.readline

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

c = []
for i in range(H):
    lis = list(map(int, input().split()))
    c.append(lis)

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*10000000+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*10000000+b
            ran.append(r)

ran.sort()
mx = 0
for r in ran:
    r1 = r % 10000000
    r0 = r // 10000000
    if(r1>=mx):
        mx = r0
        ans += 1

print(ans)