Dij A ok

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int,int>
#define vec vector
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvl(vector <ll> &v){
    for (auto x: v) cout<<x<<' ';
    cout<<"\n";
}


void cvv(vector <vector <int> > &v){
    for (auto x: v) cv(x);
    cout<<"\n";
}

void cvb(vector <bool> v){
    for (bool x: v) cout<<x<<' ';
    cout<<"\n";
}

void cvs(vector <string>  v){
    for (auto a: v){
        cout<<a<<"\n";
    }
}

const int inf = 2e9;

struct ed{
    int fr,to,w;
};



int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int n, start, finish;
    cin>>n>>start>>finish;
    start--; finish--;
    vector <int> d(n, inf);
    vector <vector <pii> > G(n);
    for (int i = 0; i < n; ++i){
        for (int j = 0; j < n;++j){
            int x; cin>>x;
            if (x == -1 || i == j) continue;
            pii e = {j, x};
            G[i].push_back(e);
        }
    }

    d[start]=0;
    set <pii> Q;//расстояние, в-на
    Q.insert({0, start});
    //e = {v, l}
    while (!Q.empty()){
        int v = Q.begin()->second;
        Q.erase(Q.begin());
        for (pii e: G[v]){
            //if (d[e.first] != inf) continue;
            if (d[e.first] > d[v] + e.second){

                Q.erase({d[e.first], e.first});
                d[e.first] = d[v] + e.second;
                Q.insert({d[e.first], e.first});
            }
        }
    }
    if (d[finish] == inf){
        cout<<-1;
        exit(0);
    }
    cout<<d[finish];
}