Main.cc: In function 'int main()':
Main.cc:6:2: error: expected ';' before 'for'
for(int i=2;i<=30;i++){
^
Main.cc:6:14: error: 'i' was not declared in this scope
for(int i=2;i<=30;i++){
^
Main.cc:6:23: error: expected ';' before ')' token
for(int i=2;i<=30;i++){
^
Main.cc:4:6: warning: unused variable 'a' [-Wunused-variable]
int a=1;
^