#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)x.size())
#define sumof(x) accumulate(all(x), 0ll)
const int N=1001;
int n, s, a[N];
void solve(int tc){
// cout << "Case #" << tc << ": ";
vector<pair<int, int>> v;
cin >> n >> s;
for (int i=1; i<=n; ++i) cin >> a[i];
function<void(int, int)> bubble_sort=[&](int l, int r) -> void {
while (1){
bool stop=true;
for (int i=l; i<r; ++i) if (a[i]>a[i+1]){
swap(a[i], a[i+1]);
stop=false;
v.emplace_back(i, i+1);
v.emplace_back(i+1, i);
v.emplace_back(i, i+1);
}
if (stop) break;
}
};
if (s==1){
for (int i=19; i>=0; --i){
vector<int> idx;
for (int j=1; j<=n; ++j) if (a[j]>>i&1) idx.push_back(j);
if (idx.empty()) continue;
int max_cnt=(1<<i);
int bit0=min(max_cnt, n-1);
for (int j=1; j<=bit0; ++j) if (a[j]>>i&1){
if (!(a[j+1]>>i&1)){
v.emplace_back(j+1, j);
a[j+1]^=a[j];
}
v.emplace_back(j, j+1);
a[j]^=a[j+1];
}
for (int j=bit0+1; j<=n; ++j) if (a[j]>>i&1){
int idx1=j, idx2=j;
while (idx1>bit0+1 && !(a[idx1-1]>>i&1)) --idx1;
while (idx2<n && !(a[idx2+1]>>i&1)) ++idx2;
for (int k=j-1; k>=idx1; --k){
v.emplace_back(k, k+1);
a[k]^=a[k+1];
}
for (int k=j+1; k<=idx2; ++k){
v.emplace_back(k, k-1);
a[k]^=a[k-1];
}
}
bubble_sort(bit0+1, n);
n=bit0;
}
}else{
for (int i=19; i>=0; --i){
vector<int> idx;
for (int j=1; j<=n; ++j) if (a[j]>>i&1) idx.push_back(j);
if (idx.empty()) continue;
for (int j=1; j<sz(idx); ++j){
int i1=idx[j-1], i2=idx[j];
for (int k=i1; k<i2-1; ++k){
v.emplace_back(k+1, k);
a[k+1]^=a[k];
v.emplace_back(k, k+1);
a[k]^=a[k+1];
}
v.emplace_back(i2-1, i2);
a[i2-1]^=a[i2];
}
if (idx.back()!=n){
for (int j=idx.back(); j<n; ++j){
v.emplace_back(j+1, j);
a[j+1]^=a[j];
v.emplace_back(j, j+1);
a[j]^=a[j+1];
}
}
--n;
}
}
cout << sz(v) << '\n';
for (auto& i:v) cout << i.first << ' ' << i.second << '\n';
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int ntests=1;
// cin >> ntests;
for (int i=1; i<=ntests; ++i) solve(i);
return 0;
}
