include <bits/stdc++.h>

using namespace std; int n;

struct o {

int sum, l;

} a[100001];

bool aa(o a, o b) {

return a.l > b.l;

} vectorg;

int main() {

cin >> n;
for (int i = 1; i <= n; i++) {
	a[i].sum = i;
	cin >> a[i].l;
}
sort(a + 1, a + 1 + n, aa);
for (int i = 1; i <= n; i++) {
	for (int j = i + 1; j <= a[i].l + i; j++) {
		a[j].l--;
		if (a[j].l < 0) {
			cout << "false";
			return 0;
		}
		g.push_back({a[i].sum, a[j].sum});
	}
	sort(a + i + 1, a + n + 1, aa);
}
cout << "true" << endl;
for (int i = 0; i < g.size(); i++) {
	cout << g[i].sum << " " << g[i].l << endl;
}
return 0;

}