PROGRAM MAIN
    IMPLICIT NONE
    CHARACTER(:), ALLOCATABLE :: S
    INTEGER :: N

    READ *, N

    ALLOCATE(CHARACTER(N / 2) :: S)
    IF (MOD(N, 2) == 0) THEN
        S = REPEAT('1', N / 2)
    ELSE
        S = '7' // REPEAT('1', N / 2 - 1)
    END IF
    PRINT *, S
END PROGRAM MAIN