#include <iostream>
#include <iomanip>
#include <vector>
#include <climits>
#include <iterator>
/* run this program using the console pauser or add your own getch, system("pause") or input loop */
using namespace std;

int ** READ(int N)
{
	int num;
	int ** M = new int * [N];
	for(int i = 0; i < N; i++)
	{
		M[i] = new int[N];
		for(int j = 0; j < N; j++)
		{
			cin >> num;
			if(num < 0)
				M[i][j] = 1000000000;
			else
				M[i][j] = num;
		}
	}
	return M;
}

void PRINT(int ** M, int N)
{
	for(int i = 0; i < N; i++)
	{
		for(int j = 0; j < N; j++)
			cout << setw(4) << M[i][j];
		cout << endl;
	}
}

int main(int argc, char** argv) {
	int N, S, F;
	int ** matrix;
	vector<int> a, b, c;
	
	cin >> N >> S >> F;
	S--;
	F--;
	
	matrix = READ(N);
	
	a.assign(N, 0);
	b.assign(matrix[S], matrix[S] + N);
	c.assign(N, S);
	a[S] = 1;
	
	/*
	PRINT(matrix, N);
	copy(a.begin(), a.end(), ostream_iterator<int>(cout, " "));
	cout << endl;
	copy(b.begin(), b.end(), ostream_iterator<int>(cout, " "));
	cout << endl;
	copy(c.begin(), c.end(), ostream_iterator<int>(cout, " "));
	cout << endl;
	*/
	
	int index = N;
	int min = INT_MAX;
	for(int i = 0; i < N; i++)
	{
		if(a[i] == 0 && b[i] < min)
		{
			index = i;
			min = b[i];
		}
	}
	
	//for(int l = 0; index < N && l < 2; l++)
	while(index < N)
	{
		a[index] = 1;
		for(int k = 0; k < N; k++)
		{
			if(b[index] + matrix[index][k] < b[k])
			{
				b[k] = b[index] + matrix[index][k];
				c[k] = index;
			}
		}
		
		min = INT_MAX;
		index = N;
		for(int i = 0; i < N; i++)
		{
			if(a[i] == 0 && b[i] < min)
			{
				index = i;
				min = b[i];
			}
		}
		/*
		copy(a.begin(), a.end(), ostream_iterator<int>(cout, " "));
		cout << endl;
		copy(b.begin(), b.end(), ostream_iterator<int>(cout, " "));
		cout << endl;
		copy(c.begin(), c.end(), ostream_iterator<int>(cout, " "));
		cout << endl;
		*/
	}
	
	if(b[F] == 1000000000) cout << -1;
	else cout << b[F];
	return 0;
}