kfactor.cpp: In function `int prim(long long int)': kfactor.cpp:14: call of overloaded `sqrt(long long int&)' is ambiguous /usr/include/bits/mathinline.h:441: candidates are: double sqrt(double) /usr/include/c++/3.2.2/cmath:465: long double std::sqrt(long double) /usr/include/c++/3.2.2/cmath:461: float std::sqrt(float)