#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
using namespace std;
const int maxn = 100100;
struct node {
public:
int value, ind;
};
node tree[3*maxn];
int n, d, m;
vector<int>tasks[maxn];
node mergef(node a, node b) {
node c;
if(a.value < b.value) {
c.value = a.value;
c.ind = a.ind;
}
else if(a.value > b.value) {
c.value = b.value;
c.ind = b.ind;
}
else if(a.value == b.value){
c.value = a.value;
c.ind = min(a.ind, b.ind);
}
return c;
}
void build(int li=1, int ri=n, int index=1) {
if(li == ri) {
tree[index].value = 0;
tree[index].ind = li;
}
else {
int mid = (li+ri)/2;
build(li,mid,2*index);
build(mid+1,ri,2*index+1);
tree[index] = mergef(tree[2*index], tree[2*index+1]);
}
}
void update(int x, int li=1, int ri=n, int index=1) {
if(li == ri) {
tree[index].value++;
tree[index].ind = x;
}
else {
int mid = (li+ri)/2;
if(x <= mid) update(x, li, mid, 2*index);
else update(x, mid+1,ri,2*index+1);
tree[index] = mergef(tree[2*index], tree[2*index+1]);
}
}
node query(int ql, int qr, int li=1, int ri=n, int index=1) {
if(li > qr || ri < ql) return {INT_MAX, INT_MAX};
else if(li >= ql && ri <= qr) return tree[index];
else {
int mid = (li+ri)/2;
return mergef(query(ql,qr,li,mid,2*index), query(ql,qr,mid+1,ri,2*index+1));
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cin>>n>>d>>m;
build();
int x, result = 0;
for(int i=1;i<=m;i++) {
cin>>x;
node curr = query(x, x+d);
//cout<<"["<<x<<", "<<x+d<<"] -> "<<curr.value<<", "<<curr.ind<<"\n";
tasks[curr.ind].pb(i);
result = max(result, int(tasks[curr.ind].size()));
update(curr.ind);
}
cout<<result<<"\n";
for(int i=1;i<=n;i++) {
for(int j:tasks[i]) {
cout<<j<<" ";
} cout<<"0\n";
}
return 0;
}
