### 问题描述 小蓝有一个 01 矩阵。他打算将第一行第一列的 $0$ 变为 $2$ 。变化过程有传染性，每次 $2$ 的上下左右四个相邻的位置中的 $0$ 都会变成 $2$ 。直到最后每个 $2$ 的周围都是 $1$ 或 $2$ 结束。 请问，最终矩阵中有多少个 $2$ ？ 以下是小蓝的矩阵，共 $30$ 行 $40$ 列。 ``` 0000100010000001101010101001001100000011 0101111001111101110111100000101010011111 1000010000011101010110000000001011010100 0110101010110000000101100100000101001001 0000011010100000111111001101100010101001 0110000110000000110100000000010010100011 0100110010000110000000100010000101110000 0010011010100110001111001101100110100010 1111000111101000001110010001001011101101 0011110100011000000001101001101110100001 0000000101011000010011111001010011011100 0000100000011001000100101000111011101100 0010110000001000001010100011000010100011 0110110000100011011010011010001101011011 0000100100000001010000101100000000000010 0011001000001000000010011001100101000110 1110101000011000000100011001001100111010 0000100100111000001101001000001010010001 0100010010000110100001100000110111110101 1000001001100010011001111101011001110001 0000000010100101000000111100110010101101 0010110101001100000100000010000010110011 0000011101001001000111011000100111010100 0010001100100000011000101011000000010101 1001111010010110011010101110000000101110 0110011101000010100001000101001001100010 1101000000010010011001000100110010000101 1001100010100010000100000101111111111100 1001011010101100001000000011000110110000 0011000100011000010111101000101110110001 ``` ### 答案提交 这是一道结果填空的题，你只需要算出结果后提交即可。本题的结果为一个整数，在提交答案时只填写这个整数，填写多余的内容将无法得分。