#include <bits/stdc++.h>
#define f first
#define s second
using namespace std;
#define int long long
const int maxn = 1e6 + 69;
vector<int> g[maxn], vis(maxn);
void dfs(int v) {
vis[v] = 1;
for(auto u : g[v]) {
if(!vis[u])
dfs(u);
}
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int tt = 1;
//cin >> tt;
while(tt--) {
int n;
cin >> n;
vector<int> a(n);
for(int i = 0;i < n;i++)
cin >> a[i];
int dp[n];
dp[0] = 1;
for(int i = 1;i < n;i++) {
dp[i] = dp[i - 1] + 1;
for(int j = i - 1;j >= 0;j--) {
if(a[j] == a[i])
break;
if(a[j] == a[i] + 1) {
dp[i] = dp[i - 1];
break;
}
}
}
cout << dp[n - 1];
}
return 0;
}
