// Slower C++ solution:
/*

                                ^....0

                               ^ .1 ^1^

                               ..     01

                              1.^     1.0

                             ^ 1  ^    ^0.1

                             1 ^        ^..^

                             0.           ^ 0^

                             .0            1 .^

                             .1             ^0 .........001^

                             .1               1. .111100....01^

                             00             ^   11^        ^1. .1^

                             1.^                              ^0  0^

                               .^                                 ^0..1

                               .1                                   1..^

                             1 .0                                     ^  ^

                            ^ 00.                                     ^^0.^

                             1 ^ 0                                     ^^110.^

                           0.   0 ^                                    ^^^10.01

                   ^^     010^   1 1                                   ^^^1110.1

                   0001  10 0   ^ 1.1                                   ^^^1111110

                   0^ 10 . 01   ^^  ^^                                   ^^^1111^1.^           ^^^

                   10  10^ 0^                                             ^^111^^^0.1^       1....^

                    11     0                                               ^^11^^^ 0..  ....1^   ^ ^

                    1.     0^                                               ^11^^^ ^ 1 111^     ^ 0.

                   10   00 11                                               ^^^^^   1 0           1.

                   0^  ^0  ^0                                                ^^^^    0            0.

                   0^  1.0  .^                                               ^^^^    1 1          .0

                   ^.^  ^^  0^                             ^1                ^^^^     0.         ^.1

                   1 ^      11                             1.                ^^^     ^ ^        ..^

                  ^..^      ^1                             ^.^               ^^^       .0       ^.0

                  0..^      ^0                              01               ^^^       ..      0..^

                 1 ..        .1                             ^.^              ^^^       1 ^  ^0001

                ^  1.        00                              0.             ^^^        ^.0 ^.1

                . 0^.        ^.^                             ^.^            ^^^         ..0.0

               1 .^^.         .^                  1001        ^^            ^^^         . 1^

               . ^ ^.         11                0.    1         ^           ^^          0.

                0  ^.          0              ^0       1                   ^^^          0.

              0.^  1.          0^             0       .1                   ^^^          ..

              .1   1.          00            .        .1                  ^^^           ..

             1      1.         ^.           0         .^                  ^^            ..

             0.     1.          .^          .         0                                  .

             .1     1.          01          .        .                                 ^ 0

            ^.^     00          ^0          1.       ^                                 1 1

            .0      00           .            ^^^^^^                                   .

            .^      00           01                                                    ..

           1.       00           10                                                   1 ^

          ^.1       00           ^.                                            ^^^    .1

          ..        00            .1                                        1..01    ..

         1.1         00           1.                                       ..^      10

        ^ 1^         00           ^.1                                      0 1      1

        .1           00            00                                       ^  1   ^

         .           00            ^.^                                        10^  ^^

       1.1           00             00                                              10^

       ..^           1.             ^.                                               1.

      0 1            ^.              00                 00                            .^

        ^            ^.              ^ 1                00   ^0000^     0               01

     1 0             ^.               00.0^              ^1.0.1   1.00.1              11

     . 1              0               1^^0.01                      ^^^                01

      .^              ^                1   1^^                                       ^.^

    1 1                                                                              0.

    ..                                                                              1 ^

     1                                                                               1

   ^ ^                                                                             .0

   1                                                                             ^ 1

   ..                                                          1.1            ^0.0

  ^ 0                                                           1..01^^100000..0^

  1 1                                                            ^ 1 ^^1111^ ^^

  0 ^                                                             ^ 1      1000^

  .1                                                               ^.^     .   00

  ..                                                                1.1    0.   0

  1.                                                                  .    1.   .^

  1.                                                                 1    1.   ^0

 ^ .                                                                 ^.1 00    01

 ^.0                                                                  001.     .^

 */

// Virtual_Judge —— Maximum Profit Aizu - ALDS1_1_D.cpp created by VB_KoKing on 2019,04,24,19.

/* Procedural objectives：



 Procedural thinking：

 在下标自增的过程中，将现阶段rt最小值保存下来。

 Functions required by the program:



 Variables required by the program:



*/

/* My dear Max said：

"I like you,

So the first bunch of sunshine I saw in the morning is you,

The first hurricane that passed through your ear is you,

The first star you see is also you.

The world I see is all your shadow."



FIGHTING FOR OUR FUTURE！！！

*/

#include <set>

#include <map>

#include <list>

#include <deque>

#include <stack>

#include <queue>

#include <cmath>

#include <cstdio>

#include <string>

#include <vector>

#include <cctype>

#include <sstream>

#include <complex>

#include <cstring>

#include <cstdlib>

#include <iostream>

#include <algorithm>

#include <functional>

using namespace std;

int main()

{

    int n;

    cin>>n;



    int rt[200000];

    memset(rt,0, sizeof(rt));



    for (int i = 0; i < n; ++i) {

        cin >> rt[i];

    }



    int maxv=-2000000000,minv=rt[0];

    for (int i = 1; i < n; i++) {       

        maxv=max(maxv,rt[i]-minv);      //更新最大值

        minv=min(minv,rt[i]);           //暂存现阶段的最小值

    }

    

    cout<<maxv<<endl;



    return 0;

}


// Faster C++ solution for the same problem (measured speedup: 1.8293079509696388x):
#include <bits/stdc++.h>

using namespace std;



int main()

{

    int n;

    scanf("%d", &n);

    int r;

    scanf("%d", &r);

    --n;

    int maxv=-2000000000, minv=r, x;

    while(n--)

    {

        scanf("%d", &x);

        maxv=max(maxv, x-minv);

        minv=min(minv, x);

    }

    printf("%d\n", maxv);

    return 0;

}