#include<bits/stdc++.h>

using namespace std;

#define Reimu inline void // 灵梦赛高
#define Marisa inline int // 魔理沙赛高
#define Sanae inline bool // 早苗赛高
#define Reisen inline LL  // 铃仙赛高

typedef long long LL;
typedef unsigned long long ULL;
typedef __int128 Suika;

inline ostream &operator<<(ostream &cout, Suika x) {
	static const LL LIM = 1e18;
	if (x < 0) cout << '-', x = -x;
	return x < LIM ? cout << LL(x) : cout << LL(x / LIM) << setw(18) << setfill('0') << LL(x % LIM);
}

typedef pair<int, int> Pii;
typedef tuple<int, int, int> Tiii;
#define fi first
#define se second

#define ALL(vec) vec.begin(), vec.end()
#define TY(type) const type&

#define BT(func) __builtin_##func
#define BTL(func) __builtin_##func##ll

template<typename Ty>
Reimu clear(Ty &x) { Ty().swap(x); }
template<typename Ty>
Reimu max_(Ty &x, TY(Ty) y) { if (y > x) x = y; }
template<typename Ty>
Reimu min_(Ty &x, TY(Ty) y) { if (y < x) x = y; }

const int N = 110;

const LL INF = 1LL << 60;

int n, m, cnt;
int q[N * N], p[N], vis[N], f[N];
LL d[N];
vector<tuple<int, int, LL>> ans;

int main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	cin >> n >> m;
	for (int i = 1; i <= m; ++i) cin >> q[i], p[q[i]] = i;
	if (p[1] > 1) return cout << "No\n", 0;
	for (int i = 1; i <= n; ++i) if (p[i]) f[++cnt] = p[i]; 
	sort(f + 1, f + cnt + 1);
	for (int i = 1; i <= n; ++i) d[i] = INF;
	LL cur = 0;
	for (int i = 1; i < cnt; ++i) {
		int l = f[i], r = f[i + 1];
		for (int i = l + 1; i <= r; ++i) {
			if (vis[q[i]]) return cout << "No\n", 0;
			vis[q[i]] = 1;
		}
		for (int i = l + 1; i < r; ++i) vis[q[i]] = 0, ans.emplace_back(q[l], q[i], --d[q[i]] - cur);
		cur += INF - d[q[l]];
		ans.emplace_back(q[l], q[r], INF - d[q[l]]);
	}
	cout << "Yes\n" << ans.size() << '\n';
	for (auto [x, y, v]: ans) cout << x << ' ' << y << ' ' << v << '\n';
	return 0;
}