#include <iostream>
#include <deque>
#include <vector>
using namespace std;
int main()
{
ios::sync_with_stdio(false);
//cin.tie(NULL);
//cout.tie(NULL);
int b,iv=0,pom;
bool open=0;
deque<int> d;
vector<int> v;
cin>>b;
while(cin>>pom)
{
v.push_back(pom);
}
for(long long i=0;i<20000000;i++)
{
if(i==v[iv]&&iv<v.size())
for(int j=0;j<v.size();j++)
if(i==v[iv])
d.push_back(v[iv++]+30);
else
break;
if(i>=d[0])
for(int j=0;j<d.size();j++)
if(i>=d[0])
d.pop_front();
else
break;
if(d.size()>b&&!open)
{
cout<<"["<<i<<" - ";
open=1;
}
if(d.size()<=b&&open)
{
cout<<i<<")\n";
open=0;
}
if(!open&&v[v.size()-1]<i)
break;
}
}
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