View Compilation Error

0_0_21071469_26976.c: In function 'main':
0_0_21071469_26976.c:9:2: error: unknown type name 'bool'
  bool flag;
  ^
0_0_21071469_26976.c:12:10: error: 'true' undeclared (first use in this function)
   flag = true;
          ^
0_0_21071469_26976.c:12:10: note: each undeclared identifier is reported only once for each function it appears in
0_0_21071469_26976.c:17:12: error: 'false' undeclared (first use in this function)
     flag = false;
            ^