View Compilation Error

0_0_19986102_21527.cpp:4:1: error: '_Bool' does not name a type
 _Bool judge(int n)
 ^
0_0_19986102_21527.cpp: In function 'int main()':
0_0_19986102_21527.cpp:26:17: error: 'judge' was not declared in this scope
   while (judge(n)!=0)
                 ^