#include <stdio.h>
#include <stdlib.h>
int main()
{
int t,n,b;
float sum,h=1;
scanf("%d",&n);
for(t=1;t<=n-1;t++)
{
for(b=1,sum=1;b<=t;b++)
{
h=h+2;
sum+=1/h;
}
h=1;
}
printf("%.3f",sum);
}
#include <stdio.h>
#include <stdlib.h>
int main()
{
int t,n,b;
float sum,h=1;
scanf("%d",&n);
for(t=1;t<=n-1;t++)
{
for(b=1,sum=1;b<=t;b++)
{
h=h+2;
sum+=1/h;
}
h=1;
}
printf("%.3f",sum);
}