View Compilation Error

0_0_29617542_29666.cpp: In function 'int main()':
0_0_29617542_29666.cpp:40:31: error: 'pf' was not declared in this scope
             if (p==1) pf("0\n");
                               ^
0_0_29617542_29666.cpp:41:26: error: 'pf' was not declared in this scope
             else pf("1\n");
                          ^
0_0_29617542_29666.cpp:44:40: error: 'pf' was not declared in this scope
         pf("%I64d\n",(pow_m(2,n)-2+p)%p);
                                        ^