#include 
#define LL long long
using namespace std;
const int N = 2e4 + 10;
int n, k, a[N], cnt;
int main()
{
	cin >> n >> k;
	for(int i = 1;i <= n;i++) cin >>a[i];
	for(int i = 1;i <= n;i++)
	{
		for(int j = i;j <= n;j++)
		{
			if(j - i >= k && a[i] == a[j])
			{
				cout << i << " " << j <<endl;
				cnt++;
			}
		}
	}
	cout << cnt <<endl;
	return 0;
}