program prob3
    implicit none
    character(len=50) :: O, E
    integer :: i, leno, lene
    read(*,*) O
    read(*,*) E

    leno = len_trim(O)
    lene = len_trim(E)

    do i = 1, lene
        write(*,'(a)',advance='no') O(i:i)
        write(*,'(a)',advance='no') E(i:i)
    end do

    if(leno > lene) then
        write(*,'(a)',advance='no') O(leno:leno)
    end if
    write(*,*)

    stop
contains
end program prob3