#include <stdio.h>
int main()
{
int n;
while(~scanf("%d",&n))
{
int i=1;
double s=0;
for(;i<=n;i++)
{
s=s+(1.0/i);
}
printf("%.4f\n",s);
}
return 0;
}
#include <stdio.h>
int main()
{
int n;
while(~scanf("%d",&n))
{
int i=1;
double s=0;
for(;i<=n;i++)
{
s=s+(1.0/i);
}
printf("%.4f\n",s);
}
return 0;
}