sust_b.cpp

#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const long double PI = acos(-1);
typedef long long int ll;
typedef unsigned long long ull;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(),x.end()
#define fo(i,n) for(int i=0;i<(int)n;i++)
#define fo1(i,n) for(int i=1;i<=(int)n;i++)
#define deb(x) cout<<#x<<"="<<x<<endl

void solve(int tc)
{
    int m, n;
    long double w, l;
    cin >> m >> w >> n;
    l = w * sqrt(2);
    while(m != n)
    {
        l = 2 * w;
        w = (w * sqrt(2));
        m--;
    }
    cout << fixed << setprecision(4);
    cout << l + w << endl;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int tc = 1;
    cin >> tc;
    fo1(t, tc)
    {
        solve(t);
    }
    return 0;
}