#include <bits/stdc++.h>

using namespace std;

const int N = 1e5+5;
int a[N], len[N], p[N], last[10*N];
struct comp {
    bool operator()(const int& l, const int& r) const {
        return len[l] == len[r] ? l < r : len[l] > len[r];
    }
};

void dfs(int x) {
    if (!x) return;
    dfs(p[x]);
    printf("%d ", a[x]);
}

int main() {
    set<int, comp> s;
    s.insert(0);
    a[0] = -2;

    int n; scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d", a+i);
        bool done = false;
        for (set<int, comp>::iterator it = s.begin(); it != s.end(); it++) {
            int j = *it;
            if (abs(a[j]-a[i]) == 1) continue;
            s.erase(i);
            len[i] = len[j] + 1;
            s.insert(i);

            p[i] = j;
            if (last[a[i]]) s.erase(last[a[i]]);
            last[a[i]] = i;
            done = true;
            break;
        }
    }

    int x = *s.begin();
    printf("%d\n", n-len[x]);
    dfs(x);
    return 0;
}