#include <iostream> using namespace std; int a[105]; int main() { int n, cnt = 1, m = 0; cin >> n; for (int i = 0; i < n; i++) { cin >> a[i]; } for (int i = 0; i < n-1; i++) { for (int j = i + 1; j < n; j++) { if (a[i] - a[j] <= 2) { cnt++; } } if (cnt > m) { m = cnt; } cnt = 1; } cout << m << endl; return 0; }