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

/* run this program using the console pauser or add your own getch, system("pause") or input loop */

int main(int argc, char *argv[]) {
	int n,i;
	double s;
	printf("n=");
	scanf("%d",&n);
	for (i=1,s=1;i<=n;i++)
	 s=s+s/(i*i);
	printf("s=%lf",s);

	return 0;
}