C

#include <bits/stdc++.h>
#define _ ios_base:sync_with_stdio(0);cin.tie(0);
using namespace std;
/*** typedef ***/
#define MEMSET_INF 127
#define MEMSET_HALF_INF 63
#define stream istringstream
#define rep(i,n) for(__typeof(n) i=0; i<(n); i++)
#define repl(i,n) for(__typeof(n) i=1; i<=(n); i++)
#define FOR(i,a,b) for(__typeof(b) i=(a); i<=(b); i++)
#define INF (1<<30)
#define PI acos(-1.0)
#define pb push_back
#define ppb pop_back
#define all(x) x.begin(),x.end()
#define mem(x,y) memset(x,y,sizeof(x))
#define memsp(x) mem(x,MEMSET_INF)
#define memdp(x) mem(x,-1)
#define memca(x) mem(x,0)
#define eps 1e-9
#define pii pair<int,int>
#define pmp make_pair
#define ft first
#define sd second
#define vi vector<int>
#define vpii vector<pii>
#define si set<int>
#define msi map<string , int >
#define mis map<int , string >
typedef long long i64;
typedef unsigned long long ui64;
/** function **/
#define SDi(x) sf("%d",&x)
#define SDl(x) sf("%lld",&x)
#define SDs(x) sf("%s",x)
#define SD2(x,y) sf("%d%d",&x,&y)
#define SD3(x,y,z) sf("%d%d%d",&x,&y,&z)
#define pf printf
#define print(x) pf("%d ", x)
#define println(x) pf("%d\n", x)
#define sf scanf
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)


i64 a[100001], n;

int main() {
#ifndef ONLINE_JUDGE
    READ("input.txt");
#endif
    int caseNo = 0;
    while(cin >> n ) {
        rep(i, n) cin >> a[i];
        i64 total = 0;
        i64 zero = 0, backup = 0;
        while (zero < n) {
            sort(a, a + n - backup, greater<i64>());
            backup = zero;
            rep(i, n - 1) {
                a[i] -= 1;
                if (a[i] == 0) zero++;
            }
            total += 1;
        }
        cout << total << "\n";
    }

    return 0;
}