Main.cc:4:5: error: expected initializer before 'int'
int a;
^
Main.cc:5:2: error: 'cin' does not name a type
cin >>a;
^
Main.cc:6:2: error: expected unqualified-id before 'if'
if(a>30){
^
Main.cc:9:2: error: expected unqualified-id before 'if'
if(a<30){
^