PROGRAMMING:Determine whether a digraph has a loop
This problem requires programming to determine whether there is a loop in a digraph
###Input format:
The input is the adjacent vertex of 1 in the adjacency matrix representation of digraph, ending with - 1 - 1
###Output format:
If there is a loop, output 1, otherwise output 0
###Input example:
```in
0 3
0 2
0 1
1 5
1 4
1 2
2 5
4 5
5 3
-1 -1
```
###Output example:
```out
0
```
answer：If there is no answer, please comment
###Input format:
The input is the adjacent vertex of 1 in the adjacency matrix representation of digraph, ending with - 1 - 1
###Output format:
If there is a loop, output 1, otherwise output 0
###Input example:
```in
0 3
0 2
0 1
1 5
1 4
1 2
2 5
4 5
5 3
-1 -1
```
###Output example:
```out
0
```
answer：If there is no answer, please comment