// editor3
#include<stdio.h>
int isPalindrome(int n)
{
    int original = n,rev = 0;
    while(n > 0)
    {
        rev = rev * 10 + (n % 10);
        n /= 10;
    }
    return rev == original;
}
int main()
{
    int n;
    char temp[100];
    if (!fgets(temp, sizeof(temp), stdin))
    {
        printf("Invalid input");
        return 0;
    }
    for (int i = 0; temp[i] != '\0'; i++)
    {
        if(temp[i] == '\n')break;
        if(temp[i] == '_' || temp[i] == '-')
        {
            printf("Invalid input");
            return 0;
        }
        if(temp[i] < '0' || temp[i] > '9')
        {
            printf("Invalid input");
            return 0;
        }
    }
    sscanf(temp, "%d", &n);
    if(n < 0)
    {
        printf("Invalid input");
        return 0;
    }
    in
}