#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define N 1000001
#define ff first
#define ss second
#define pb push_back
#define sz(s) (int)s.size()
int n, t, m, jog[N], sum, cnt = 1, a[N];
deque <int> v[N], h[N];
int main () {
ios::sync_with_stdio(0);cin.tie(0);
cin >> n >> m;
for(int i = 1;i <= n; i++) {
cin >> a[i];
sum += a[i];
}
if(sum % m != 0) {
cout << "-1\n";
return 0;
}
for(int i=1;i<=n;i++) {
if(sum / a[i] < m) {
cout << "-1\n";
return 0;
}
}
for(int i = 1; i <= n; i++) {
if(jog[cnt] == sum / m) cnt++;
if(jog[cnt] + a[i] <= sum / m) {
v[cnt].pb(a[i]);
h[cnt].pb(i);
jog[cnt] += a[i];
continue;
}
v[cnt].pb(sum / m - jog[cnt]);
h[cnt].pb(i);
a[i] -= (sum / m - jog[cnt]);
jog[cnt] += (sum / m - jog[cnt]);
cnt++;
v[cnt].pb(a[i]);
h[cnt].pb(i);
jog[cnt] += a[i];
}
vector <ll> ans;
while(sz(v[1]) > 0) {
int mn = v[1][0];
cout<< mn << '\n';
bool tr = 0;
for(int i = 1; i <= m; i++) {
mn = min(mn,v[i][0]);
}
ans.pb(mn);
for(int i=1;i<=m;i++) {
ans.pb(h[i][0]);
}
for(int i = 1; i <= m; i++) {
v[i][0] -= mn;
if(!v[i][0]) {
h[i].pop_front();
v[i].pop_front();
}
}
}
cout << sz(ans) / (m + 1) << '\n';
for(int i = 0; i < sz(ans); i++) {
cout << ans[i] << " ";
if(i % (m + 1) == m) cout << '\n';
}
}
