编写一个词法器，让你输入的代码有合适的标号如：if标号为1，a标号为2，；标号为3 <,>标号为4.等等。-The preparation of a lexical, and let you enter the code a suitable label such as: if labeling for 1, a label for 2 labeling 3 <,> grade 4. And so on.

该程序可以将你存在文件中的字符进行分栏，标号操作。-The program can put you in the document the existence of characters in column, labeling operation.

首先读取一串列标号，这些列标号成对出现，表示输入行的列范围。这串列标号以一个负值结尾，作为结束标志。剩余的输入行被程序读入并打印，然后输入行中被选中范围的字符串被提取出来并打印。注意，每行第1列的列标号为零-First reads a serial label, label these columns appear in pairs, which means input line column range. This serial label with a negative end, as th