#include using namespace std; using ll = long long; #define all(A) A.begin(),A.end() using vll = vector; #define rep(i, n) for (long long i = 0; i < (long long)(n); i++) using Graph = vector>; ll mod=998244353; ll inva(ll N) { ll a = N, b = mod, c = 1, d = 0; while (b > 0) { ll t = a / b; a -= t * b; swap(a, b); c -= t * d; swap(c, d); } c %= mod; if (c < 0)c += mod; return c; }//割り算時に使う逆元を求める. int main() { ll H,W,N; cin>>H>>W>>N; vector C(H,vll(W)); rep(h,H)rep(w,W)cin>>C[h][w]; vector> Q; rep(h,H)rep(w,W-1){ Q.push_back(make_pair(max(C[h][w],C[h][w+1]),min(C[h][w],C[h][w+1]))); } rep(h,H-1)rep(w,W){ Q.push_back(make_pair(max(C[h][w],C[h+1][w]),min(C[h][w],C[h+1][w]))); } sort(all(Q)); ll R=-1; ll an=0; rep(q,Q.size()){ if(Q[q].second>R){ R=Q[q].first; an++; } } cout<