60pts

#include <bits/stdc++.h>
using namespace std;

int n, a[1005];

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n;
    int mx = 0;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        if (a[i] > mx)
            mx = a[i];
    }
    int ans = 0;
    for (int h = 1; h <= mx; h++)
        for (int i = 1; i <= n; i++)
            if (a[i] < h && (i == 1 || a[i - 1] >= h))
                ans++;
    cout << ans << "\n";
    return 0;
}

std