农场灌溉问题（）

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 irrigation problems () shown in a farm by a map composed of 11 kinds of small squares, blue line for the irrigation channels. If the adjacent two of the irrigation canal is connected to only one well irrigation. Gives the maximum number of letters that do not exceed 50 × 50 concrete by the (m, n), said the farm plan, program calculated the minimum number required to play the wells. The output of each test case of a line. When M = N =- 1 o' clock program.