from collections import deque import sys sys.setrecursionlimit(10**6) class MaxFlow: inf = 10**18 class E: def __init__(self,to,cap): self.to = to self.cap = cap self.rev = None def __init__(self,n): self.n = n self.graph = [[] for _ in range(n)] def add_edge(self, fr, to, cap): graph = self.graph edge = self.E(to,cap) edge2 = self.E(fr,0) edge.rev = edge2 edge2.rev = edge graph[fr].append(edge) graph[to].append(edge2) def bfs(self, s, t): level = self.level = [self.n]*self.n q = deque([s]) level[s] = 0 while q: now = q.popleft() lw = level[now]+1 for e in self.graph[now]: if e.cap and level[e.to]> lw: level[e.to] = lw if e.to == t: return True q.append(e.to) return False def dfs(self, s, t, up): graph = self.graph it = self.it level = self.level st = deque([t]) while st: v = st[-1] if v == s: st.pop() flow = up for w in st: e = graph[w][it[w]].rev flow = min(flow, e.cap) for w in st: e = graph[w][it[w]] e.cap += flow e.rev.cap -= flow return flow lv = level[v]-1 while it[v] < len(graph[v]): e = graph[v][it[v]] re = e.rev if re.cap == 0 or lv != level[e.to]: it[v] += 1 continue st.append(e.to) break if it[v] == len(graph[v]): st.pop() level[v] = self.n return 0 def flow(self,s,t,flow_limit=inf): flow = 0 while flow < flow_limit and self.bfs(s,t): self.it = [0]*self.n while flow < flow_limit: f = self.dfs(s,t,flow_limit-flow) if f == 0: break flow += f return flow def min_cut(self,s): visited = [0]*self.n q = deque([s]) while q: v = q.pop() visited[v] = 1 for e in self.graph[v]: if e.cap and not visited[e.to]: q.append(e.to) return visited h,w = map(int,input().split()) A = [list(map(int,input().split())) for i in range(h)] xy = [[] for i in range(5*10**5+5)] for i in range(h): for j in range(w): xy[A[i][j]].append((i,j)) ans = 0 for i in range(5*10**5,0,-1): if xy[i] == []: continue s = h+w t = s+1 maxflow = MaxFlow(t+1) for j in range(h): maxflow.add_edge(s, j, 1) for j in range(w): maxflow.add_edge(h+j, t, 1) for x,y in xy[i]: maxflow.add_edge(x, h+y, 1) ans += maxflow.flow(s, t) print(ans)