#include<iostream.h>

int N, A;
int where[1001];
int start[1001];
int *y;
short line[1001];
int  hows;

void main()
{
int i, j;
 y = new int[32000];
  cin>>N>>A;
    for (i=1; i<=N; i++)
        where[i] = 0;
    hows=0;
    for (i=1; i<=N; i++)
    {
        for (j=1; j<=N; j++) cin>>line[j];
        for (j=i%N+1; j!=i; j=j%N+1)
            if (line[j]==0)
            {
                where[i]++;
                y[hows]=j;
                hows++;
            }
    }
    start[1]=0;
    for (i=2; i<=N; i++)
        start[i]=where[i-1]+start[i-1];
    i = A;
    j = y[start[i]];
    while (hows>0)
    {
        start[i]++;
        cout<<i<<" "<<j<<endl;
        hows--;
        i = j;
        j = y[start[i]];
    }
 delete[] y;
}