>>219
#include <stdio.h>
int main(void) {
    int r, n = 0;
    double x, t = 1, a = 1;
    printf("x?:"); scanf("%lf", &x);
    printf("r?:"); scanf("%d", &r);
    while (n++ < r) a += t *= x / n;
    printf("%f", a);
    return 0;
}