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

#define numbers stdin

int main(void) {
    int x, a;
    float sum = 0;
    /*
    FILE * numbers;
    numbers = fopen("source.txt", "r");
    
    if (!numbers) {
        perror("\aError");
        exit(EXIT_FAILURE);}
    */
    printf("Enter x value: ");
    scanf("%d", &x);
    
    while(fscanf(numbers, "%d", &a)==1){
        sum*=x;
        sum+=a;}
    
    printf("\nAnswer: %g\n", sum);
    
    return 0;
}