Given the adjacency matrix of an undirected graph with `n` vertices, determine and print the number of isolated vertices. A vertex is **isolated** if its degree is 0, meaning it is not an endpoint of any edge (the corresponding row of the adjacency matrix contains only `0` values). Input: The first line contains the natural number `n`. The following `n` lines each contain `n` binary values, representing the adjacency matrix. - `1 <= n <= 50` - the matrix is symmetric with `0` on the main diagonal Output: The program prints to standard output a single non-negative integer: the number of isolated vertices in the graph. Example: Input: 5 0 1 1 0 0 1 0 0 1 0 1 0 0 0 1 0 1 0 0 0 0 0 1 0 0 Output: 0