#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vl = vector<ll>;
template<class T> using vc = vector<T>;
template<class T> using vvc = vector<vector<T>>;

#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define repr(i, n) for (ll i = (n)-1; i >= 0; i--)
#define repe(i, l, r) for (ll i = (l); i < (r); i++)
#define reper(i, l, r) for (ll i = (r)-1; i >= (l); i--)
#define repa(i,n) for (auto& i: n)

template<class T1, class T2> inline bool chmax(T1 &a, const T2 &b) {if (a<b) { a=b; return 1;} return 0;}
template<class T1, class T2> inline bool chmin(T1 &a, const T2 &b) {if (b<a) { a=b; return 1;} return 0;}
struct init{init(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}}init_;

#ifdef DEBUG
template <class T, class N> void verr(const T& a, const N& n) { rep(i, n) cerr << a[i] << " "; cerr << "\n" << flush; }
ll dbgt = 1; void err() { cerr << "passed " << dbgt++ << "\n" << flush; }
template<class H, class... T> void err(H&& h,T&&... t){ cerr<< h << (sizeof...(t)?" ":"\n") << flush; if(sizeof...(t)>0) err(forward<T>(t)...); }
#endif

const ll INF = 4e18;
const ld EPS = 1e-11;
const ld PI = acos(-1.0L);
const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
//--------------------------------------------------------------------------------//
struct UnionFind {
private:
    vector<int> par;
    vector<int> count;
    vector<int> rank;
public:
    UnionFind(int N) {
        count.assign(N, 1);
        rank.assign(N, 0);
        par.assign(N, 0);
        rep(i, N) par[i] = i;
    }

    int root(int x) {
        if (par[x] == x)
            return x;
        else {
            par[x] = root(par[x]);
            return par[x];
        }
    }

    void unite(int x, int y) {
        x = root(x), y = root(y);
        if (x == y) return;
        if (rank[x] < rank[y])
            swap(x, y);
        else if (rank[x] == rank[y])
            rank[y]++;
        par[y] = x;
        count[x] += count[y];
        return;
    }

    int size(int x) {
        return count[root(x)];
    }

    bool issame(int x, int y) {
        return root(x) == root(y);
    }
};
using UF = struct UnionFind;

int main() {
    ll N;
    cin >> N;
    vc<string> S(N);
    rep(i, N) cin >> S[i];

    vvc<int> child(N), parent(N);
    rep(i, N){
        vl srch(N);
        srch[i] = true, child[i].eb(i);
        queue<ll> q;
        q.emplace(i);
        while(!q.empty()){
            ll now = q.front();
            q.pop();
            rep(j, N){
                if (srch[j] or S[now][j] == '0') continue;
                srch[j] = true;
                child[i].eb(j);
                q.emplace(j);
            }
        }
        srch = vl(N), q.emplace(i), parent[i].eb(i), srch[i] = true;
        while(!q.empty()){
            ll now = q.front();
            q.pop();
            rep(j, N){
                if (srch[j] or S[j][now] == '0') continue;
                srch[j] = true;
                parent[i].eb(j);
                q.emplace(j);
            }
        }
    }

    ld ans = 0;
    rep(i, N) ans += 1.0L / parent[i].size();

    cout << ans << endl;
}
#include<bits/stdc++.h>
#define ll long long 
#define pb push_back
#define ff first
#define ss second
#define setbits(x)          __builtin_popcountll(x)
#define lp(a,n) for(ll i=a; i<n; i++)
#define lpi(a,n) for(int i=a; i<n; i++)
#define w(t) int t; cin>>t; while(t--)
#define vi vector<int> 
#define vll vector<ll>
#define pll pair<ll, ll>
#define pii pair<int, int>
#define inf 1e9
#define LB lower_bound
#define UB upper_bound
const int mod = 1000000007;
using namespace std;
ll gcd(ll a,ll b){
    if(a==0)return b;
    return gcd(b%a,a);
}
ll lcm(ll a, ll b){
    return (a*b)/gcd(a,b);
}
 
int prime[100007];
void SieveOfEratosthenes(int n) 
{ 
    memset(prime, -1, sizeof(prime)); 
  
    for (int p=2; p*p<=n; p++) 
    { 
         
        if (prime[p] == -1) 
        { 
            for (int i=p*p; i<=n; i += p) 
                prime[i] = p; 
        } 
    } 
    
} 
int lps(string s){
    int len = 0;
    int n = s.length();
    int dp[n];
    dp[0] = 0;
    for(int i=1; i<n; i++){
        if(s[i] == s[len]){
            len++;
            dp[i] = len;
            continue;
        }
        if(len!=0){
            len = dp[len-1];
            i--;
            continue;
        }
        dp[i]=0;
    }
    return dp[n-1];
}
 
ll power(unsigned ll x,unsigned  ll y) 
{ 
    ll res = 1;     
    while (y > 0) 
    { 
        if (y & 1) 
            res = res*x; 
   
        y = y>>1;
        x = x*x;  
    } 
    return res; 
}
 
//to calculate p1^x  *  p2^x2  *p3^x3 ----------
//i.e. prime factorization and store pi and xi in vector 
vector<pair<ll, ll>> pFactor;
 
void factorize(long long n) 
{ 
    int count = 0; 
  
    // count the number of times 2 divides  
    while (!(n % 2)) { 
        n >>= 1; // equivalent to n=n/2; 
        count++; 
    } 
  
    // if 2 divides it 
    if (count) 
        pFactor.pb({2,count}); 
  
    // check for all the possible numbers that can  
    // divide it 
    for (long long i = 3; i <= sqrt(n); i += 2) { 
        count = 0; 
        while (n % i == 0) { 
            count++; 
            n = n / i; 
        } 
        if (count) 
            pFactor.pb({i,count});
    } 
  
    // if n at the end is a prime number. 
    if (n > 2) 
        pFactor.pb({n,1}); 
} 

 
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
    string s;
    cin>>s;
    if(s[0]==s[1] and s[1]==s[2]){
        cout<<"Won\n";
    }else cout<<"Lost\n";
}
