View Compilation Error

0_0_20659364_6209.cpp: In function 'int Nim_Multi(int, int)':
0_0_20659364_6209.cpp:29:45: error: 'Nim_Multi_power' was not declared in this scope
  return M*(c1^c2)^c3^Nim_Multi_power(M>>1,c1);
                                             ^