Main.cc: In function 'int main()':
Main.cc:6:8: error: unable to find numeric literal operator 'operator""or'
if(a==1or 3or 5){
^
Main.cc:6:8: note: use -std=gnu++11 or -fext-numeric-literals to enable more built-in suffixes
Main.cc:6:12: error: expected ')' before numeric constant
if(a==1or 3or 5){
^