#include <bits/stdc++.h>
using namespace std;
#include <atcoder/segtree>
using namespace atcoder;

const int INF = 1e9;
int op(int a, int b) { return max(a, b); }
int e() { return -INF; }

int main()
{
  int N, Q;
  string S;
  cin >> N >> Q >> S;

  vector<int> cum0(N + 1, 0), cum1(N + 1, 0);
  for (int i = 0; i < N; i++)
  {
    cum0.at(i + 1) = cum0.at(i);
    cum1.at(i + 1) = cum1.at(i);
    if (S.at(i) == '0')
      cum0.at(i + 1)++;
    else
      cum1.at(i + 1)++;
  }

  vector<int> RLE_left = {0}, RLE_right = {0}, RLE_len = {1};
  vector<int> where(N, 0);
  for (int i = 1; i < N; i++)
  {
    if (S.at(i - 1) == S.at(i))
    {
      RLE_right.back()++;
      RLE_len.back()++;
    }
    else
    {
      RLE_left.push_back(i);
      RLE_right.push_back(i);
      RLE_len.push_back(1);
    }
    where.at(i) = (int)RLE_left.size() - 1;
  }

  segtree<int, op, e> seg(RLE_len);

  while (Q--)
  {
    int L, R, K;
    cin >> L >> R >> K;
    L--, R--;

    int l = where.at(L), r = where.at(R);
    bool ok = false;
    if (RLE_right.at(l) - L + 1 >= K)
      ok = true;
    else if (R - max(L, RLE_left.at(r)) + 1 >= K)
      ok = true;
    else
    {
      l++, r--;
      if (l <= r && seg.prod(l, r + 1) >= K)
        ok = true;
    }
    if (!ok)
    {
      cout << R - L + 1 << endl;
      continue;
    }

    int x = cum0.at(R + 1) - cum0.at(L);
    int y = cum1.at(R + 1) - cum1.at(L);
    int z = (x - y) % (2 * K - 1);
    if (z < 0)
      z += 2 * K - 1;
    cout << max(z - 1, 2 * K - 2 - z) << endl;
  }
}