#include <stdio.h>
#define MAX_SIZE 100

int top = -1;
char stack[MAX_SIZE];

void push(char c) {
    if (top < MAX_SIZE - 1) {
        stack[++top] = c;
    }
}

char pop() {
    if (top >= 0) {
        return stack[top--];
    }
    return '\0';
}

int is_palindrome(char *str) {
    int i;
    for (i = 0; str[i] != '\0'; i++) {
        push(str[i]);
    }

    for (i = 0; str[i] != '\0'; i++) {
        if (str[i] != pop()) {
            return 0;
        }
    }
    return 1;
}

int main() {
    char str[MAX_SIZE];
    printf("Enter a string: ");
    scanf("%s", str);

    if (is_palindrome(str)) {
        printf("%s is a palindrome.\n", str);
    } else {
        printf("%s is not a palindrome.\n", str);
    }

    return 0;
}