View Compilation Error

0_0_24439237_14040.c:4:1: error: unknown type name 'bool'
 bool check(int n,int flag){    
 ^
0_0_24439237_14040.c: In function 'check':
0_0_24439237_14040.c:6:10: error: 'false' undeclared (first use in this function)
   return false;
          ^
0_0_24439237_14040.c:6:10: note: each undeclared identifier is reported only once for each function it appears in
0_0_24439237_14040.c:9:11: error: 'true' undeclared (first use in this function)
    return true;
           ^