
/*
TASK: oldmap
LANG: C
*/

#include<stdio.h>

int a[500][500];
int b[500][500]={0};
int i,j,k,n;

int main(){
    scanf("%d",&n);
    for ( i=0;i<n;i++)
        for (j=0;j<n;j++)
            scanf("%d",&a[i][j]);

    for (k=0;k<n;k++)
        for (i=0;i<n;i++)
            for (j=0;j<n;j++)
                if (a[i][k]+a[k][j]<a[i][j]){
                   a[i][j]=a[i][k]+a[k][j];
                   b[i][j]=0;
                   }
                   else
                       if (a[i][k]+a[k][j]==a[i][j]&&i!=k&&j!=k)
                          b[i][j]=1;

    for (i=0;i<n;i++)
        for (j=i+1;j<n;j++)
           if (!b[i][j])
              printf("%d %d %d\n",i+1,j+1,a[i][j]);
    return 0;
    }
