Main.cc: In function 'int main()': Main.cc:8:11: error: expected unqualified-id before '>>' token double>>a>>b; ^ Main.cc:9:12: error: unable to find string literal operator 'operator""a' with 'const char [5]', 'long unsigned int' arguments printf("%.2d"a/b) ^ Main.cc:7:9: warning: unused variable 'a' [-Wunused-variable] int a,b; ^