https://pintia.cn/problem-sets/1556843855285559296/exam/problems/type/7?problemSetProblemId=1556843936151740417&page=0

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> PII;
typedef vector<long long> VI;
#define int long long
#define INF 0x3f3f3f3f
#define endl '\n'
#define N 200010
const int mod = 1e9 + 7;

ll lowbit(ll x) {
    return -x & x;
}

int p[N], si[N];
int find(int x) {
    if (x == p[x])return p[x];
    p[x] = find(p[x]);
    return p[x];
}
//size[find(b)] += size[find(a)];
//p[find(a)] = find(b);

//bool cmp(pair<int, int> a, pair<int, int> b){
//  return a.f
//}
void solve() {
    int n;
    cin >> n;

    vector<pair<int, int>> time;
    int a[1010];
    a[n + 1] = 1e9;
    for (int i = 1; i <= n; i ++)cin >> a[i];

    int red = 0, l = 0, r = 0, add = 0;
    for (int i = 1; i <= n + 1; i++) {

        if (!red) {
            red = 1;

            l = a[i] + 15;
            r = l + 29;
        }

        else {
            if (a[i] < l)continue;
            if (a[i] > r) {
                add = 0, red = 0;

//              time.push_back({l, r});
                cout << l << " " << r << endl;
                i --;
                continue ;
            }

            if (!add) {
                add = 1;
                r += 15;
            }
        }

    }
//
//  if (r)time.push_back({l, r});
//
//  for (auto [l, r] : time) {
//      cout << l << " " << r << endl;
//  }
}

signed main() {

    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T = 1;
//  cin >> T;
    while (T --)

        solve();

    return 0;
}