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

int main()
{   
    int i,c;
    double x;
    long double result=0;
    scanf("%lF",&x);
    long double *array;
    array = (long double*) malloc(10000);
    for(i=0,c=1;i<c;i++,c++){
        int b = scanf("%Lf",&array[i]);
        if(b==EOF){
            break;
        }
    }
    for(int j=0 ;i>0; i--,j++){
    result+=(long double)(array[j]*pow(x,i-1));
    }
//    if(result>=10000&&result<1000000000000){
//        result=((int)(result*100-0.5)/100);
//    }    
    printf("%.2Lf",result);
    free(array);
    return 0;
}