// 2023 IUSB Programming Competition
// Round 1 Problem 3
// Gold Price
// Solution by Liguo Yu

#include <iostream>
#include <vector>

using namespace std;

int main()
{
    int bYear, n;
    cin >> bYear >> n;
    
    vector<float> price(n);
    
    for(int i=0; i<n; i++)
    {
        cin >> price[i];
    }
    
    double max = (price[1] - price[0]) / price[0];
    int index = 0;
    
    for(int i=1; i<n; i++)
    {
        if((price[i] - price[i-1]) / price[i-1] > max)
        {
            max = (price[i] - price[i-1]) / price[i-1];
            index = i-1;
        }
    }
    int year = bYear + index;
    int next_year = year + 1;
    cout << year << " - " << next_year << endl;
}