/in/foo.c: In function 'FindMaxNeg':
/in/foo.c:10:2: error: 'max' undeclared (first use in this function)
  max=-9999;
  ^~~
/in/foo.c:10:2: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:14:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^