#include <bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 1e18;
const int mxN = 3e5 + 10;
struct segment_tree{
vector<int> seg, lazy;
int N;
void init(int n){
seg.resize(mxN * 4, inf);
lazy.resize(mxN * 4, 0);
N = n;
}
void push(int node, int start, int end){
if(lazy[node] == 0) return;
seg[node] += lazy[node];
if(start ^ end){
lazy[node * 2 + 1] += lazy[node];
lazy[node * 2 + 2] += lazy[node];
}
lazy[node] = 0;
}
void pull(int node){
seg[node] = min(seg[node * 2 + 1], seg[node * 2 + 2]);
}
void update(int node, int start, int end, int l, int r, int x){
push(node, start, end);
if(start > r || end < l) return;
if(start >= l && end <= r){
lazy[node] = x;
push(node, start, end);
return;
}
int mid = start + (end - start) / 2;
update(node * 2 + 1, start, mid, l, r, x);
update(node * 2 + 2, mid + 1, end, l, r, x);
pull(node);
}
void update(int node, int start, int end, int idx, int v){
push(node, start, end);
if(start == end){
seg[node] = v;
return;
}
int mid = start + (end - start) / 2;
if(idx <= mid) update(node * 2 + 1, start, mid, idx, v);
else update(node * 2 + 2, mid + 1, end, idx, v);
pull(node);
}
int query(int node, int start, int end, int l, int r){
push(node, start, end);
if(start > r || end < l) return inf;
if(start >= l && end <= r) return seg[node];
int mid = start + (end - start) / 2;
return min(query(node * 2 + 1, start, mid, l, r), query(node * 2 + 2, mid + 1, end, l, r));
}
int query(int l, int r){
return query(0, 1, N, l, r);
}
void update(int idx, int v){
update(0, 1, N, idx, v);
}
void update(int l, int r, int v){
update(0, 1, N, l, r, v);
}
} tr;
signed main(){
ios::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
int n, ans = 0;
cin >> n; tr.init(n);
for(int i = 1, x; i <= n; ++i){
cin >> x;
tr.update(i, x);
}
for(int i = 1; i <= n; ++i){
int cur = tr.query(i, i);
if(cur == 0) continue;
ans += 1;
int st = i, en = n, best = i;
while(st <= en){
int mid = st + (en - st) / 2;
if(tr.query(i, mid) >= cur){
st = mid + 1;
best = mid;
}else{
en = mid - 1;
}
}
tr.update(i, best, -cur);
}
cout << ans << "\n";
return 0;
}
