#include<bits/stdc++.h>
using namespace std;
int daysnum, maxdelay, reqnum;
vector<int> requests(1e6 + 10);
vector<int> prefreq(2 * 1e6, 1e8);
vector<stack<int>> numind(1e6 + 10);
vector<int> inp(1e6 + 1);
bool valid(int machnum) {
int index = 1;
while(index <= daysnum) {
if(inp[index] > maxdelay) {
if(prefreq[index + maxdelay - 1] - prefreq[index - 1] > machnum * maxdelay ) {
return false;
}
}
index++;
}
return true;
}
int main() {
cin >> daysnum >> maxdelay >> reqnum;
for(int i = 0 ;i < reqnum; i++) {
int time;
cin >> time;
inp[i + 1] = time;
requests[time]++;
numind[time].push(i + 1);
}
int l = 0;
int r = 1e6 + 1;
prefreq[0] = 0;
for(int i = 1; i <= 1e6; i++) {
prefreq[i] = requests[i] + prefreq[i - 1];
}
while(l < r) {
int mid = (l + r) / 2;
if(valid(mid)) {
r = mid;
}
else {
l = mid + 1;
}
}
int minmach = l;
int cur = minmach;
cout << minmach << endl;
int day = 1;
int curday = 1;
while(day <= daysnum) {
int used = 0;
while(used < minmach) {
if(curday > day) {
break;
}
else if(numind[curday].empty()) {
curday++;
}
else {
int ans = numind[curday].top();
cout << ans << " ";
numind[curday].pop();
}
used++;
}
cout << 0 << endl;
day++;
}
}
