View Compilation Error

0_0_30026143_20641.cpp: In function 'LL get(LL)':
0_0_30026143_20641.cpp:48:18: error: 'MN' was not declared in this scope
  LL st = 1, en = MN, md;
                  ^
0_0_30026143_20641.cpp:50:3: error: 'md' was not declared in this scope
   md = (st + en) / 2;
   ^