#include <stdio.h>
#include <string.h>
#include <ctype.h>
int main() {
    char s[101];
    fgets(s, 101, stdin);
    s[strcspn(s, "\n")]= 0;
    
    for (int i = 0; s[i]; i++){
        if (!isalpha(s[i]) && s[i] != ' ') {
            printf("Invalid input");
            return 0;
        }
    }

    char *word = strtok(s," ");
    while (word) {
        for (int i = strlen(word) - 1; i >=0; i--)
        printf("%c", word[i]);
        word - strtok(NULL," ");
        if (word) printf(" ");
    }
    return 0;
}