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

#define MAX_LINE_LENGTH 256

bool IsValidNumber(const char *line) {
    char *endFtr;
    strtod(line, &endFtr);
    return endFtr != line;
}

int main() {
    char line[MAX_LINE_LENGTH];
    double result = 1;
    int coefficientIndex = 0;

    printf("Zadajte zaklad x: ");
    if (fgets(line, MAX_LINE_LENGTH, stdin) == NULL || !IsValidNumber(line)) {
        printf("Nepodarilo sa nacitat zaklad x\n");
        return 1;
    }

    while (1) {
        if (fgets(line, MAX_LINE_LENGTH, stdin) == NULL || !IsValidNumber(line)) {
            if (line[0] == '\n') {
                break;
            }
            printf("Nepodarilo sa nacitat polynom na %d mieste. \n", coefficientIndex);
            return 1;
        }

        char *endPtr;
        double x = strtod(line, &endPtr);
        if (*endPtr != '\n' && *endPtr != '\0') {
            printf("Nespravny format cisla\n");
            return 1;
        }

        result = result * x;
        coefficientIndex++;
    }

    printf("Vysledok je: %.2f\n", result);
    return 0;
}