#include <Eigen/Core>
#include <iostream>

int main()
{
    int const N = 5;
    Eigen::MatrixXi A(N,N);
    A.setRandom();
    std::cout << "A =\n" << A << '\n' << std::endl;
    std::cout << "A(1..3,:) =\n" << A.middleCols(1,3) << std::endl;
    return 0;
}