Main.cc: In function ‘int main()’: Main.cc:5:8: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(a); ^ In file included from /usr/include/stdio.h:862:0, from /usr/include/c++/7/cstdio:42, from /usr/include/c++/7/ext/string_conversions.h:43, from /usr/include/c++/7/bits/basic_string.h:6361, from /usr/include/c++/7/string:52, from Main.cc:1: /usr/include/x86_64-linux-gnu/bits/stdio2.h:232:1: note: declared here gets (char *__str) ^~~~ Main.cc:6:10: error: ‘strlen’ was not declared in this scope int len=strlen(a); ^~~~~~ Main.cc:6:10: note: suggested alternative: ‘mbrlen’ int len=strlen(a); ^~~~~~ mbrlen Main.cc:13:3: error: expected ‘;’ before ‘}’ token } ^ Main.cc:16:3: error: expected ‘;’ before ‘}’ token } ^ Main.cc:18:2: error: ‘cout’ was not declared in this scope cout<