Problem:
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Maximum Profit

You can obtain profits from foreign exchange margin transactions. For example, if you buy 1000 dollar at a rate of 100 yen per dollar, and sell them at a rate of 108 yen per dollar, you can obtain (108 - 100) × 1000 = 8000 yen.

Write a program which reads values of a currency $R_t$ at a certain time $t$ ($t = 0, 1, 2, ... n-1$), and reports the maximum value of $R_j - R_i$ where $j > i$ .

Input

The first line contains an integer $n$. In the following $n$ lines, $R_t$ ($t = 0, 1, 2, ... n-1$) are given in order.

Output

Print the maximum value in a line.

Constraints

$2 \leq n \leq 200,000$

$1 \leq R_t \leq 10^9$

Sample Input 1

6
5
3
1
3
4
3

Sample Output 1

3

Sample Input 2

3
4
3
2

Sample Output 2

-1

Solution in C (judge verdict: Accepted)

#include <stdio.h>
#define MIN -1e9

int Maxmum(int a,int b){
    return ( (a>b) ? a : b );
}

int Minimum(int a,int b){
    return ((a<b) ? a : b); 
}

int main(){
    int t;
    scanf("%d",&t);
    int maxtmp,mintmp;
    int r[t];
    for(int i=0; i<t; i++) scanf("%d",&r[i]);

    mintmp = r[0];
    maxtmp = MIN;

    for(int i=1; i<t; i++){
        maxtmp = Maxmum(maxtmp,r[i]-mintmp);
        mintmp = Minimum(mintmp,r[i]);
    }

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

    return 0;
}