一农场由图所示的十一种小方块组成，蓝色线条为灌溉渠。若相邻两块的灌溉渠相连则只需一口水井灌溉。给出若干由字母表示的最大不超过50×50具体由(m，n)表示，的农场图，编程求出最小需要打的井数。每个测例的输出占一行。当M=N=-1时结束程序。
　
,Farm by the one shown in Figure 11 kinds of components in small box, blue lines for the irrigation canals. If two adjacent connected to the irrigation canal is only an irrigation wells. Give a number of letters that do not exceed the maximum 50 × 50 concrete from (m, n), said the farm plan, the minimum programming required to derive the number of playing well. Example output for each test line. When M = N =- 1 pm program.