#include <bits/stdc++.h>
using namespace std;
int main ()
{
    int n,a,b,i,v[101];
    cin>>n;
    for(i=1;i<=n;i++) cin>>v[i];
    for(i=1;i<n;i++)
    {
        a=v[i]+1;
        b=v[i+1]-1;
        if(a<=b) cout<<a<<"-"<<b<<endl;
    }
    a=v[n]+1;
    if(a<=100) cout<<a<<"-"<<100;
}