View Compilation Error

0_0_17507930_17913.cpp:16:11: error: '::main' must return 'int'
 long main()  
           ^
0_0_17507930_17913.cpp: In function 'int main()':
0_0_17507930_17913.cpp:23:30: error: 'prlongf' was not declared in this scope
             prlongf("sorry\n");  
                              ^
0_0_17507930_17913.cpp:28:48: error: 'prlongf' was not declared in this scope
             prlongf("%lld %lld\n",x,(1-(x)*a)/b);  
                                                ^