cc1plus.exe: error: '::main' must return 'int' 0_0_39408138_2061.cpp: In function 'int main()': 0_0_39408138_2061.cpp:19:17: error: 'prlong' was not declared in this scope; did you mean 'long'? 19 | prlong longf("%.2lf%%\n",a); | ^~~~~~ | long