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

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  
  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;
  }

  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 - RLE_left.at(r) + 1 >= K)
      ok = true;
    else
    {
      for (int i = l + 1; i <= r - 1; i++)
      {
        if (RLE_len[i] >= K)
        {
          ok = true;
          break;
        }
      }
    }
    if (!ok)
    {
      cout << R - L + 1 << '\n';
      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) << '\n';
  }
}