PROGRAM-ID.                      ABC_102_D.
ENVIRONMENT                      DIVISION.
INPUT-OUTPUT                     SECTION.
FILE-CONTROL.
    SELECT SYSIN ASSIGN TO KEYBOARD ORGANIZATION LINE SEQUENTIAL.

DATA                             DIVISION.
FILE                             SECTION.
    FD  SYSIN.
        01 INDATA PIC X(2200000).

WORKING-STORAGE                  SECTION.
    01 INF     PIC 9(15) VALUE 999999999999999.

    01 INP     PIC X(2200000).

    01 N       PIC 9(6).
    01 maxlen  PIC 9(6).
    01 cur     PIC 9(7) VALUE 1.
    01 len     PIC 9(7).

    01 i       PIC 9(6) VALUE 1 BINARY.
    01 j       PIC 9(6) BINARY.

    01 ret     PIC 9(6).

    01 li      PIC 9(6).
    01 ri      PIC 9(6).

    01 lv      PIC 9(15).
    01 rv      PIC 9(15).

    01 st      PIC 9(6).
    01 ed      PIC 9(6).
    01 bk      PIC 9(6).

    01 ms      PIC 9(6).

    01 ans     PIC X(15).

    01 x       PIC 9(10).

    01 sm      PIC 9(15).
    01 tmp     PIC 9(15).
    01 tmp2    PIC 9(15).

    01 mx      PIC 9(15).
    01 mn      PIC 9(15).

    01 flg     PIC 9(1).

    01 P       PIC 9(15).
    01 Q       PIC 9(15).
    01 R       PIC 9(15).
    01 S       PIC 9(15).

    01 ZS      PIC Z(15)9.
    01 DUMMY   PIC X(1).

    01 A1.
        03 A11 OCCURS 200000 DEPENDING ON maxlen INDEXED AX1 AX2.
            05 A PIC 9(15).

PROCEDURE                        DIVISION.
    ACCEPT N.

    OPEN INPUT SYSIN.

    READ SYSIN INTO INP.

    CLOSE SYSIN.

    MOVE N TO maxlen.

    MOVE ZERO TO bk.

    PERFORM maxlen TIMES

        PERFORM VARYING j FROM cur BY 1
            UNTIL INP(j:1) = SPACE
        END-PERFORM

        COMPUTE len = j - cur

        MOVE INP(cur:len) TO x

        ADD x TO tmp

        SET AX1 TO i

        MOVE tmp TO A(AX1)

        COMPUTE cur = j + 1

        ADD 1 TO i

    END-PERFORM.

    MOVE 1 TO li.
    MOVE 1 TO ri.

    MOVE INF TO sm.

    PERFORM VARYING i FROM 2 BY 1 UNTIL N - 1 <= i
        COMPUTE st = 1
        COMPUTE ed = i
        COMPUTE bk = li

        PERFORM F

        MOVE ret TO li

        IF ri < i + 1
            COMPUTE ri = i + 1
        END-IF

        COMPUTE st = i + 1
        COMPUTE ed = N
        COMPUTE bk = ri

        PERFORM F

        MOVE ret TO ri

        SET AX1 TO li
        COMPUTE P = A(AX1)

        SET AX1 TO i
        COMPUTE Q = A(AX1) - P

        SET AX1 TO ri
        SET AX2 TO i
        COMPUTE R = A(AX1) - A(AX2)

        SET AX2 TO N
        COMPUTE S = A(AX2) - A(AX1)

        COMPUTE mx = FUNCTION MAX(P, Q, R, S)

        COMPUTE mn = FUNCTION MIN(P, Q, R, S)

        IF mx - mn < sm
            COMPUTE sm = mx - mn
        END-IF
    END-PERFORM.

    MOVE sm TO ZS.

    PERFORM UNANS.

    DISPLAY ans(1:FUNCTION STORED-CHAR-LENGTH(ans)).
    STOP RUN.

UNANS                            SECTION.
    UNSTRING
        ZS DELIMITED BY ALL SPACE
        INTO DUMMY ans
    END-UNSTRING.

F                                SECTION.
    MOVE INF TO tmp
    MOVE 1 TO ret
    MOVE ZERO TO flg
    PERFORM VARYING j FROM bk BY 1 UNTIL ed < j
        SET AX1 TO j
        COMPUTE lv = A(AX1)

        IF st NOT = 1
            COMPUTE ms = st - 1
            SET AX2 TO ms
            COMPUTE lv = A(AX1) - A(AX2)
        END-IF

        SET AX2 TO ed
        COMPUTE rv = A(AX2) - A(AX1)


        IF lv < rv
            COMPUTE tmp2 = rv - lv
        ELSE
            COMPUTE tmp2 = lv - rv
        END-IF

        IF tmp2 < tmp
            COMPUTE tmp = tmp2
            COMPUTE ret = j
            MOVE 1 TO flg
        ELSE
            IF 1 = flg
                EXIT PERFORM
            END-IF
        END-IF
    END-PERFORM.
