View Compilation Error

0_0_4182761_14349.cpp: In function `int main()':
0_0_4182761_14349.cpp:47: error: `N' undeclared (first use this function)
0_0_4182761_14349.cpp:47: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_4182761_14349.cpp:49: error: `stu' undeclared (first use this function)