View Compilation Error

0_0_35800159_12836.cpp: In function 'bool judge(int)':
0_0_35800159_12836.cpp:6:57: error: 'isYD' was not declared in this scope
     if((inp-13)%5==0 && (inp-13)>0) b1 = isYD((inp-13)/5); 
                                                         ^
0_0_35800159_12836.cpp:7:57: error: 'isYD' was not declared in this scope
     if((inp+13)%5==0 && (inp+13)>0) b2 = isYD((inp+13)/5);
                                                         ^
0_0_35800159_12836.cpp:8:57: error: 'isYD' was not declared in this scope
     if((inp-5)%13==0 && (inp-5) >0) b3 = isYD((inp-5)/13);
                                                         ^
0_0_35800159_12836.cpp:9:57: error: 'isYD' was not declared in this scope
     if((inp+5)%13==0 && (inp+5) >0) b3 = isYD((inp+5)/13);
                                                         ^