#include <stdio.h>

int main()
{
	double epsilon = 1e-15;
	double work1, work2, work3;
	int d;
	work2 = 16.0 / 5.0;
	work1 = work2;
	d = 1;
	do {
		work2 /= (double)(5 * 5);
		d += 2;
		work3 = work2 / (double)d;
		if ((d & 2) == 0) {
			work1 += work3;
		} else {
			work1 -= work3;
		}
	} while(work2 > epsilon && work3 > epsilon);
	work2 = 4.0 / 239.0;
	work1 -= work2;
	d = 1;
	do {
		work2 /= (double)(239 * 239);
		d += 2;
		work3 = work2 / (double)d;
		if ((d & 2) == 0) {
			work1 -= work3;
		} else {
			work1 += work3;
		}
	} while(work2 > epsilon && work3 > epsilon);
	printf("%18.16f\n", work1);
	return 0;
}