Main.cc: In function 'int main()': Main.cc:4:30: warning: variable 'a3' set but not used [-Wunused-but-set-variable] char a1[51]={},a2[51]={},a3[53]={}; ^ Main.cc: At global scope: Main.cc:16:9: error: 'cout' does not name a type cout<a3<<endl; ^ Main.cc:17:5: error: expected unqualified-id before 'return' return 0; ^ Main.cc:18:1: error: expected declaration before '}' token } ^