#include <bits/stdc++.h>
using namespace std;
#define maxn 1005
#define pii pair<int,int>
vector<pii> ans;
int a[maxn],n;
void solve1(){
vector<int> p;
for(int i=1;i<=n;i++) p.push_back(a[i]);
sort(p.begin(),p.end());
for(int i=1;i<=n;i++) a[i]=lower_bound(p.begin(),p.end(),a[i])-p.begin()+1;
for(int i=n;i>=2;i--) ans.push_back({i,i-1});
for(int i=1;i<n;i++){
int id=-1;
for(int j=i;j<=n;j++){
if(a[j]==i) id=j;
}
while(id!=i){
if(id!=n) ans.push_back({id+1,id});
ans.push_back({id-1,id});swap(a[id-1],a[id]);
id--;
}
ans.push_back({i+1,i});
}
}
void solve2(){
for(int i=19;i>=0;i--){
bool c=false;
for(int j=1;j<=n;j++){
if(a[j]>=(1<<(i+1))) break;
if(c){
if(a[j]&(1<<i)){ans.push_back({j-1,j});a[j-1]^=a[j];}
else{
ans.push_back({j,j-1});ans.push_back({j-1,j});
a[j]^=a[j-1];a[j-1]^=a[j];
}
}
else if(a[j]&(1<<i)) c=true;
}
}
}
int main(){
//freopen("XORSORT.INP","r",stdin);
//freopen("XORSORT.OUT","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int s;cin >> n >> s;
for(int i=1;i<=n;i++) cin >> a[i];
if(s==1) solve1();
else solve2();
cout << (int)ans.size() << '\n';
for(pii x:ans) cout << x.first << ' ' << x.second << '\n';
}
