Increasing Array

#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    cin >> n;
    int a;
    int b;
    long long result=0;
    cin >> a;
    for(int i=1;i<n;++i){
            cin >> b;
            if(b<a)result+=(a-b);
            a=b;
    }
    cout << result;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: ACCEPTED

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: ACCEPTED