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

#define SIZE 256
#define MAX 1000

int main() {


    double x;
    double field[MAX];
    int k = 0;
    char line[SIZE];
    char* end;

    char* r = fgets(line,SIZE,stdin);
    if (r == NULL){
        printf("Chyba: nacitanie sa nepodarilo.\n");
        return 1;
}
    x = strtod(line, &end);

    if(end == line){
        printf("Chyba: nacitanie sa nepodarilo.\n");
        return 1;
}

while(r != NULL){
    if(line[0] == '\n'){
        break;
    }
    field[k] = strtod(line, &end);
    
    if(end == line){
        printf("Chyba: nacitanie sa nepodarilo.\n");
        return 1;
    }
    k++;
}

double result = field[0];
for(int i = 1; i < k; i++){
    result = result * x + field[i];
}
   printf("%.2f\n", result);
}