#include<cstdio>
#include<cmath>

const double r = 0.57721566490153286060651209;

void solve()
{
    int t;
    scanf("%d", &t);
    for (int i = 1; i <= t; i++)
    {
        int n;
        scanf("%d", &n);
        if (n <= 100000)
        {
            double ans = 0;
            for (int i = 1; i <= n; i++)
                ans += 1.0 / i;
            printf("Case %d: %.10lf\n", i, ans);
        }
        else
            printf("Case %d: %.10lf\n", i,  log(n) + r + 1.0 / (2 * n));
    }
}

int main()
{
    freopen("Testin.txt", "r", stdin);
    solve();
    return 0;
}