#include<stdio.h>
int main()
{int num;int sum = 0;int count = 0;scanf("%d",&num);while( num != 0 ){sum += num;count++;num--;}printf("%f",sum*1.0/count);return 0;
}
#include<stdio.h>
int main()
{int num;int sum = 0;int count = 0;scanf("%d",&num);while( num != 0 ){sum += num;count++;num--;}printf("%f",sum*1.0/count);return 0;
}