e-olymp
Problems

From adjacency matrix to the list of edges

From adjacency matrix to the list of edges

The simple not oriented graph is given by the adjacency matrix. Print its representation as a list of edges.

Input

The first line contains the number n (1n100) of vertices in a graph. Each of the next n lines contains n elements - the description of adjacency matrix.

Output

Print the list of edges, ordered by the first vertex in a pair that describes an edge.

Time limit 1 second
Memory limit 128 MiB
Input example #1
3
0 1 1
1 0 1
1 1 0
Output example #1
1 2
1 3
2 3