timus 1010

#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <math.h>
using namespace std;
long n;
long A[100010];



int main()
{
	long i;
	float gap;
	long score;
	scanf("%ld",&n);
	
	for (i=1;i<=n;i++)
		scanf("%ld",&A[i]);

	gap =fabs(A[2]*1.0-A[1]);
	score =1;

	for (i=1;i<n;i++)
	{
		if(fabs(A[i+1]*1.0 - A[i])> gap)
		{
			gap = fabs(A[i+1]*1.0 - A[i]);
			score =i;
		}	

	}

	printf("%ld %ld/n",score,score+1);
	return 0;
}