C语言版本

#include <stdio.h>
#include <string.h>

int main() {
    char content[10001];
    int length;
    scanf("%[^\n]", content, &length);
    length = strlen(content);
    char reverse[length+1];
    for (int i = 0; i < length; i++) {
        reverse[i] = content[length-i-1];
    }
    reverse[length] = '\0';
    printf("%s\n", reverse);
    return 0;
}

Python版本

print(input()[::-1])