#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <cmath>
#include <memory.h>
#include <ext/rope>
using namespace std;
using namespace __gnu_cxx;
typedef long long ll;

const int N = 1e6+6;


int main(){
   // freopen("input.txt","r",stdin);// freopen("output.txt","w",stdout);

    int n = 51;

    vector<rope<int> > f(n);

    f[0] = rope<int>(0);
    f[1] = rope<int>(1);

    for(int i=2;i<n;++i){
        f[i] = f[i-2];
        f[i].insert(0, f[i-1]);
        cout<<i<<": "<<f[i].size()<<' '<<f[i][f[i].size()/2]<<endl;

    }

    return 0;
}