You are developing a program for a social network that analyzes the friendship table. Table 1 means that people are friends, 0 are not. The table should be symmetrical, since friendship is a mutual phenomenon (if a friend b, then b friend a). The program checks the correctness of the table.
Input format
constructing the matrix, where each line contains numbers 0 and 1, separated by spaces
The input ends with the word end
Output format
Yes-if the table is symmetrical
no-if the table is a table asymmetric
Hint
There will be no clue here, decide for yourself!