Main.cc: In function 'int main()': Main.cc:6:2: error: expected ',' or ';' before 'a' a*a; ^ Main.cc:9:3: warning: statement has no effect [-Wunused-value] a*a; ^ Main.cc:12:3: warning: statement has no effect [-Wunused-value] a*a; ^ Main.cc:15:3: warning: statement has no effect [-Wunused-value] a*a; ^ Main.cc:18:3: warning: statement has no effect [-Wunused-value] a*a; ^