/in/foo.cc: In function 'int main()':
/in/foo.cc:13:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(str);    
     ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:2:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:13:13: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(str);    
             ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /usr/include/x86_64-linux-gnu/c++/6/bits/stdc++.h:46,
                 from /in/foo.cc:2:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:17:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
             if(str[i]>='a'&&str[i]<='z')   
             ^~
/in/foo.cc:19:17: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
                 i++;
                 ^
/tmp/cceeZJI5.o: In function `main':
foo.cc:(.text.startup+0xc): warning: the `gets' function is dangerous and should not be used.