#include <stdio.h>

int main(void)
{
    float x, sum, d;
    int i;
    printf("Sisesta arv: ");
    scanf("%f", &x);
    sum = 0;
    d = x;
    for (i = 1; i <= 21; d = (d * x / i++))
    {
        if ((i % 2) == 1)
        {
            sum = sum + d;
            d = -d;
        }
    }
    printf("%0.3f ", sum);
    return 0;
}