#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#define forin for(int i = 1; i <= n; i++)
#define stforin for(int i = 0; i < n; i++)
#define forim for(int i = 1; i <= m; i++)
#define forjn for(int j = 1; j <= n; j++)
#define forch(j, n) for(int i = j; i <= n; i++)
#define forch2(i, j, n) for(int i = j; i <= n; i++)
#define forjm for(int j = 1; j <= m; j++)
#define lol long long
#define lb long double
#define endl '\n'
#define debug cout << "Completed" << endl;
#define fix(n, m) cout << fixed; cout.precision(b); cout << n << endl
#define Yes cout << "YES" << endl
#define No cout << "NO" << endl
#define bads cout << -1 << endl
#define pll pair<lol, lol>
#define mod 998244353
#define inf 1e15
lol gcd(lol a, lol b) {
while (a != 0 && b != 0) if (a > b) a %= b; else b %= a;
return a + b;
}
lol lcm(lol a, lol b) {
return a / gcd(a, b) * b;
}
bool issqrt(lol n) {
lb x = sqrt(n);
if (x == (lol)x) return 1;
return 0;
}
lol easy(lol n) {
if (n == 1) return 0;
for (int i = 2; i * i <= n; i++) if (n % i == 0) return 0;
return 1;
}
string bin(lol v) {
string ans;
while (v != 0) {
ans += to_string((v % 2));
v /= 2;
}
return ans;
}
//priority_queue <pll, vector<pll>, greater<pll>> q
const long long N = 210;
lol ts, n, a[N], hmm, v1, v2, s, f[N], l, x;
vector<pll> ans;
void solve() {
cin >> n >> s;
a[0] = -1;
forin cin >> a[i];
a[n + 1] = a[n] + 10;
while (hmm == 0 && ans.size() < 40000) {
hmm = 1;
forin if (a[i] >= a[i + 1] || a[i] >= a[i - 1]) {
hmm = 0;
if (f[i] == 0 && i < n) {
a[i] ^= a[i + 1];
ans.push_back({ i, i + 1 });
}
else if (f[i] == 1 && 1 < i) {
a[i] ^= a[i - 1];
ans.push_back({ i, i - 1 });
}
f[i] = (f[i] % 2 == 0);
if (ans.size() >= 40000) break;
}
}
cout << ans.size() << endl;
x = 1;
for (auto el : ans) cout << el.first << " " << el.second << endl;
}
int main() {
ts = 1;
//cin >> ts;
while (ts--) solve();
return 0;
}
