el.cpp: In function `int main()': el.cpp:30: `z' undeclared (first use this function) el.cpp:30: (Each undeclared identifier is reported only once for each function it appears in.) el.cpp:33: `cate' undeclared (first use this function) el.cpp:35: `b' undeclared (first use this function) el.cpp:36: `s' undeclared (first use this function)