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Time Limit: 1 s Memory Limit: 1024 MB Total points: 100

#3750. 全 1 子矩阵

統計

Bobo 写了一个 $n$ 行 $m$ 列的矩阵 $A_{i, j}$.

  • 首先,他把所有元素 $A_{i, j}$ ($1 \leq i \leq n, 1 \leq j \leq m$) 设为 0.
  • 然后,他选了 $4$ 个整数 $x_1, x_2, y_1, y_2$ 满足 $1 \leq x_1 \leq x_2 \leq n, 1 \leq y_1 \leq y_2 \leq m$,并把满足 $x_1 \leq i \leq x_2, y_1 \leq j \leq y_2$ 的元素 $A_{i, j}$ 设为 1.

给出 $n$ 行 $m$ 列的矩阵 $A_{i, j}$, 判断它是否是 Bobo 所写的矩阵。

输入格式

输入文件包含多组数据,请处理到文件结束。

每组数据的第一行包含两个整数 $n$ 和 $m$.

接下来 $n$ 行,其中第 $i$ 行包含 $m$ 个整数 $A_{i, 1}, A_{i, 2}, \dots, A_{i, m}$.

  • $1 \leq n, m \leq 10$
  • $A_{i, j} \in \{0, 1\}$
  • 至多 $1000$ 组数据。

输出格式

对于每组数据,如果所给矩阵是 Bobo 所写的矩阵,输出 Yes, 否则输出 No.

样例输入

2 2
11
10
3 3
000
001
000
3 4
1111
1111
1111

样例输出

No
Yes
Yes
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