#include #include #include #include #include using namespace std; int main() { int n; cin >> n; vector v(n); vector f(110, 0); for(int i = 0; i < n; ++i) { cin >> v[i]; f[v[i]]++; } int ans = 0; for(int i = 0; i< n; i++){ int right = f[v[i] + 1]; ans = max(ans, f[v[i]] + right); } cout << ans << endl; return 0; }