#include <bits/stdc++.h>
using namespace std;
const double pi = acos(0.0) * 2.0;
const long double eps = 1e-10;
const int step[8][2] = {{-1, 0}, {0, 1}, {1, 0},  {0, -1},
                        {-1, 1}, {1, 1}, {1, -1}, {-1, -1}};
template <class T>
inline T abs1(T a) {
  return a < 0 ? -a : a;
}
template <typename t, typename t1>
t min1(t a, t1 b) {
  return a < b ? a : b;
}
template <typename t, typename... arg>
t min1(t a, arg... arr) {
  return min1(a, min1(arr...));
}
template <typename t, typename t1>
t max1(t a, t1 b) {
  return a > b ? a : b;
}
template <typename t, typename... arg>
t max1(t a, arg... arr) {
  return max1(a, max1(arr...));
}
inline int jud(double a, double b) {
  if (abs(a) < eps && abs(b) < eps)
    return 0;
  else if (abs1(a - b) / max(abs1(a), abs1(b)) < eps)
    return 0;
  if (a < b) return -1;
  return 1;
}
template <typename t>
inline int jud(t a, t b) {
  if (a < b) return -1;
  if (a == b) return 0;
  return 1;
}
template <typename it, typename t1>
inline int find(t1 val, it a, int na, bool f_small = 1, bool f_lb = 1) {
  if (na == 0) return 0;
  int be = 0, en = na - 1;
  if (*a <= *(a + na - 1)) {
    if (f_lb == 0)
      while (be < en) {
        int mid = (be + en + 1) / 2;
        if (jud(*(a + mid), val) != 1)
          be = mid;
        else
          en = mid - 1;
      }
    else
      while (be < en) {
        int mid = (be + en) / 2;
        if (jud(*(a + mid), val) != -1)
          en = mid;
        else
          be = mid + 1;
      }
    if (f_small && jud(*(a + be), val) == 1) be--;
    if (!f_small && jud(*(a + be), val) == -1) be++;
  } else {
    if (f_lb)
      while (be < en) {
        int mid = (be + en + 1) / 2;
        if (jud(*(a + mid), val) != -1)
          be = mid;
        else
          en = mid - 1;
      }
    else
      while (be < en) {
        int mid = (be + en) / 2;
        if (jud(*(a + mid), val) != 1)
          en = mid;
        else
          be = mid + 1;
      }
    if (!f_small && jud(*(a + be), val) == -1) be--;
    if (f_small && jud(*(a + be), val) == 1) be++;
  }
  return be;
}
template <class T>
inline T lowb(T num) {
  return num & (-num);
}
inline int bitnum(unsigned int nValue) { return __builtin_popcount(nValue); }
inline int bitnum(int nValue) { return __builtin_popcount(nValue); }
inline int bitnum(unsigned long long nValue) {
  return __builtin_popcount(nValue) + __builtin_popcount(nValue >> 32);
}
inline int bitnum(long long nValue) {
  return __builtin_popcount(nValue) + __builtin_popcount(nValue >> 32);
}
inline int bitmaxl(unsigned int a) {
  if (a == 0) return 0;
  return 32 - __builtin_clz(a);
}
inline int bitmaxl(int a) {
  if (a == 0) return 0;
  return 32 - __builtin_clz(a);
}
inline int bitmaxl(unsigned long long a) {
  int temp = a >> 32;
  if (temp) return 32 - __builtin_clz(temp) + 32;
  return bitmaxl(int(a));
}
inline int bitmaxl(long long a) {
  int temp = a >> 32;
  if (temp) return 32 - __builtin_clz(temp) + 32;
  return bitmaxl(int(a));
}
long long pow(long long n, long long m, long long mod = 0) {
  if (m < 0) return 0;
  long long ans = 1;
  long long k = n;
  while (m) {
    if (m & 1) {
      ans *= k;
      if (mod) ans %= mod;
    }
    k *= k;
    if (mod) k %= mod;
    m >>= 1;
  }
  return ans;
}
template <class t1, class t2>
inline void add(t1 &a, t2 b, int mod = -1) {
  if (mod == -1) mod = 1000000007;
  a += b;
  while (a >= mod) a -= mod;
  while (a < 0) a += mod;
}
template <class t>
void output1(t arr) {
  for (int i = 0; i < (int)arr.size(); i++) cerr << arr[i] << ' ';
  cerr << endl;
}
template <class t>
void output2(t arr) {
  for (int i = 0; i < (int)arr.size(); i++) output1(arr[i]);
}
const int maxn = 200100;
int orig[maxn], sum[maxn], diff[maxn], avg;
int st[maxn], lst, rst;
pair<long long, pair<long long, long long> > nxt[maxn][20];
int n, k;
unordered_map<int, int> ump;
vector<vector<int> > ans;
int GetSum(int a, int b) {
  if (a > b) {
    return sum[n - 1] - sum[a - 1] + sum[b];
  } else {
    int ans = sum[b];
    if (a) ans -= sum[a - 1];
    return ans;
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  scanf("%d%d", &n, &k);
  for (int i = 0; i < n; i++) {
    scanf("%d", orig + i);
    sum[i] = orig[i];
    if (i) sum[i] += sum[i - 1];
  }
  avg = sum[n - 1] / n;
  for (int i = 0; i < n; i++) {
    diff[i] = sum[i] - (i + 1) * avg;
  }
  for (int i = 0; i < n; i++) nxt[i][0] = make_pair(-1, make_pair(0, 0));
  for (int i = 0; i < k - 1; i++) {
    ump.clear();
    for (int j = i; j < n * 2; j += k - 1) {
      int last_no = (j - 1 + n) % n, cur_no = j % n;
      ump[diff[last_no]] = last_no;
      if (ump.find(diff[cur_no]) != ump.end()) {
        int to = ump[diff[cur_no]];
        if (to >= cur_no) {
          nxt[cur_no][0] = make_pair(
              to, make_pair((cur_no - to + n - 1) / (k - 1), cur_no - to + n));
        } else if ((cur_no - to) % (k - 1) == 1 || k == 2) {
          nxt[cur_no][0] = make_pair(
              to, make_pair((cur_no - to - 1) / (k - 1), cur_no - to));
        }
      }
    }
  }
  for (int i = 0; i < n; i++)
    if (nxt[i][0].first == -1) {
      nxt[i][0].second = make_pair((n - 1 - 1) / (k - 1) + 1,
                                   ((n - 1 - 1) / (k - 1) + 1) * (k - 1) + 1);
      nxt[i][0].first = (i - nxt[i][0].second.second % n + n) % n;
    }
  for (int i = 0; i < 17; i++) {
    for (int j = 0; j < n; j++) {
      int to = nxt[j][i].first;
      pair<long long, long long> rl = nxt[j][i].second;
      nxt[j][i + 1] = make_pair(
          nxt[to][i].first, make_pair(nxt[to][i].second.first + rl.first,
                                      nxt[to][i].second.second + rl.second));
    }
  }
  pair<long long, long long> tans = make_pair(n, -1);
  for (int i = 0; i < n; i++) {
    pair<long long, long long> ans = make_pair(0, 0);
    int last = i;
    for (int j = 17; j >= 0; j--) {
      if (nxt[last][j].second.second + ans.second < n) {
        ans.first += nxt[last][j].second.first;
        ans.second += nxt[last][j].second.second;
        last = nxt[last][j].first;
      }
    }
    long long rans = ans.first;
    if (nxt[last][0].second.second != 1) {
      rans += max(1ll, (n - ans.second - 1 - 1) / (k - 1) + 1);
    }
    if (rans < tans.first) {
      tans = make_pair(rans, i);
    }
  }
  printf("%d\n", (int)tans.first);
  if (tans.first == (n - 1 - 1) / (k - 1) + 1) {
    for (int i = 0; i < n; i++) {
      if (GetSum(i, (i + k - 1) % n) > avg * k) {
        tans.second = (i + k - 1) % n;
        break;
      }
    }
  }
  int cnt = 0, i, already = 0;
  for (i = tans.second; cnt < n;) {
    lst = 0, rst = 0;
    int delta = 0;
    int cur = i;
    int rcnt = 0;
    auto push = [&]() {
      st[rst++] = orig[cur];
      delta += avg - orig[cur];
      cur = (cur - 1 + n) % n;
      rcnt++;
    };
    push();
    for (; rcnt < nxt[i][0].second.second && ans.size() < tans.first;) {
      do {
        for (int t = 0; t < k - 1; t++) {
          push();
        }
      } while (delta > 0 && rcnt < nxt[i][0].second.second);
      if (rst > 1) {
        for (int p = (cur + 1) % n, rdelta = delta, have = 0; rst > 1;
             p = (p + k - 1) % n, rst -= k - 1) {
          long long sum1 = 0, sum2 = 0;
          for (int t = 0; t < k; t++) sum1 += orig[(p + t) % n];
          vector<int> p1;
          p1.push_back(p);
          p1.push_back(!have * -delta + avg);
          orig[p] = !have * -delta + avg;
          sum2 += !have * -delta + avg;
          for (int t = 1; t < k - 1; t++) {
            p1.push_back(avg);
            orig[(t + p) % n] = avg;
            sum2 += avg;
          }
          p1.push_back(sum1 - sum2);
          ans.push_back(p1);
          orig[(k - 1 + p) % n] = sum1 - sum2;
          rdelta = avg - sum1 + sum2;
          have = 1;
        }
        rst = lst = 0;
        st[rst++] = -delta + avg;
      }
    }
    cnt += nxt[i][0].second.second;
    i = nxt[i][0].first;
  }
  for (int i = 0; i < tans.first; i++) {
    for (int a : ans[i]) {
      printf("%d ", a);
    }
    puts("");
  }
  return 0;
}
