> #include<iostream>
> using namespace std;
> int r, c;
> int map[110][110];
> int vis[110][110];
> int dr[4][2] = { 1,0,    -1,0,   0,1,   0,-1 };
> int dfs(int x,int y) {
> 	if (vis[x][y] != 0) {
> 		return vis[x][y];
> 	}
> 	int temp = 0;
> 	for (int i = 0; i < 4; i++) {
> 		int x0 = x + dr[i][0];
> 		int y0 = y + dr[i][1];
> 		if (x0 > r || x0<1 || y0>c || y0 < 1)continue;
> 		if (map[x0][y0] >= map[x][y])continue;
> 		if (temp < dfs(x0, y0)) {
> 			temp = dfs(x0, y0);
> 		}
> 	}
> 	vis[x][y] = 1 + temp;
> 	return 1 + temp;
> }
> 
> int main() {
> 	cin >> r >> c;
> 	for (int i = 0; i < 110; i++) {
> 		for (int j = 0; j < 110; j++) {
> 			vis[i][j] = 0;
> 		}
> 	}
> 	//获取地图数据
> 	for (int i = 1; i <= r; i++) {
> 		for (int j = 1; j <= c; j++) {
> 			cin >> map[i][j];
> 		}
> 	}
> 	//开始处理
> 	int ans = -1;
> 	for (int i = 1; i <= r; i++) {
> 		for (int j = 1; j <= c; j++) {
> 			vis[i][j] = dfs(i, j);
> 			if (ans < vis[i][j])ans = vis[i][j];
> 			if (ans == r*c) {
> 				break;
> 			}
> 		}
> 		if (ans == r*c) {
> 			break;
> 		}
> 	}
> 	cout << ans<<endl;
> }