Main.cc: In function ‘int main()’: Main.cc:6:37: error: ‘setprecision12’ is not a member of ‘std’ std::cout << std::fixed << std::setprecision12) << n; ^~~~~~~~~~~~~~ Main.cc:6:37: note: suggested alternative: ‘setprecision’ std::cout << std::fixed << std::setprecision12) << n; ^~~~~~~~~~~~~~ setprecision