// 1.2 Implement a function void reverse(char *str) in C or C++ which reverses a null-terminated string.

 #include <cstdio>

 #include <cstring>

 using namespace std;

 void reverse(char *str)

 {

     if (nullptr == str) {

         return;

     }

     size_t i;

     size_t len = strlen(str);

     char ch;

     for (i = ; i < len -  - i; ++i) {

         ch = str[i];

         str[i] = str[len -  - i];

         str[len -  - i] = ch;

     }

 }

 int main()

 {

     char str[];

     while (scanf("%s", str) == ) {

         reverse(str);

         printf("%s\n", str);

     }

     return ;

 }