#include    <fstream>

using namespace std;

ifstream fin("5.in");
ofstream fout("5.out");

int main()
{
    int n, M[100][100];

    fin >> n;

    for (int i = 0; i < n; i ++)
        for (int j = 0; j < n; j ++)
            fin >> M[i][j];

    for (int i = 0; i < n; i ++)
        for (int j = 0; j < n; j ++)
            if (i + j == n + 1)
            {
                int F = 0, N[2] = {1, 1};

                while (F <= M[i][j])
                {
                    F = N[0] + N[1];
                    N[1] = N[0];
                    N[0] = F;
                }

                if (F == M[i][j])
                    fout << M[i][j];
            }

    return 0;
}