n=int(input())
l=[int(x) for x in input().split()]
l.sort()
count=1
for i in range(0,len(l)):
if(l[i]>=count):
count+=1
print(count-1)#include <bits/stdc++.h>
using namespace std;
int main()
{
#ifndef ONLINE_JUDGE
freopen("input.text", "r", stdin);
freopen("outputs.text", "w", stdout);
#endif
int n;
cin>>n;
vector<int> v;
for(int i=0; i<n; i++){
int x;
cin>>x;
v.push_back(x);
}
sort(v.begin(), v.end());
int day=0;
for(int i=0; i<n; i++){
if(v[i]>day){
day++;
}
else{
continue;
}
}
cout<<day<<endl;
return 0;
}
394. Decode String | 902. Numbers At Most N Given Digit Set |
221. Maximal Square | 1200. Minimum Absolute Difference |
1619B - Squares and Cubes | 1619A - Square String |
1629B - GCD Arrays | 1629A - Download More RAM |
1629C - Meximum Array | 1629D - Peculiar Movie Preferences |
1629E - Grid Xor | 1629F1 - Game on Sum (Easy Version) |
2148. Count Elements With Strictly Smaller and Greater Elements | 2149. Rearrange Array Elements by Sign |
2150. Find All Lonely Numbers in the Array | 2151. Maximum Good People Based on Statements |
2144. Minimum Cost of Buying Candies With Discount | Non empty subsets |
1630A - And Matching | 1630B - Range and Partition |
1630C - Paint the Middle | 1630D - Flipping Range |
1328A - Divisibility Problem | 339A - Helpful Maths |
4A - Watermelon | 476A - Dreamoon and Stairs |
1409A - Yet Another Two Integers Problem | 977A - Wrong Subtraction |
263A - Beautiful Matrix | 180C - Letter |