# include <fstream>
# include <cstring>
# include <algorithm>
# define NR 20000
using namespace std; ifstream f("substr.in"); ofstream g("substr.out"); struct elem {     int nr1, nr2, i; }var[NR]; bool cmp (elem x, elem y) {     if (x.nr1 > y.nr1) return 0;         else if (x.nr1==y.nr1 && x.nr2 >= y.nr2) return 0;             else return 1; }  struct elem2 {     int i, poz; }ind[NR]; bool cmp2 (elem2 x, elem2 y) {      if (x.poz >= y.poz) return 0;                     else return 1; }  int i,j,n,m,x,y,K,sol,VV; int lg[NR], P[20][3*NR]; char s[3*NR];  int lca (int x, int y) {     int sol=0;     x=ind[x].i; y=ind[y].i;      for (int i=lg[n]; i>=0 && x<=n && y<=n; --i) {         if (P[i][x]==P[i][y]) {             x+=(1<<i);             y+=(1<<i);             sol+=(1<<i);         }     }     return sol; } void logaritmi () {     for (int i=2; i<=n; ++i)         lg[i]=lg[i/2]+1; } int main () {     f>>n>>K; f.get();     f.getline(s+1, NR);     for (i=1; i<=n; ++i) {         P[0][i]=s[i];         s[i+n]='$';         s[i+2*n]='$';     }     logaritmi ();      for (i=1; i<=lg[n]+1; ++i) {         for (j=1; j<=n; ++j) {             var[j].nr1=P[i-1][j];             var[j].nr2=P[i-1][j+(1<<(i-1))];             var[j].i=j;         }         sort (var+1, var+n+1, cmp);          VV=0;         for (j=1; j<=n; ++j) {             if (var[j].nr1!=var[j-1].nr1 || var[j].nr2!=var[j-1].nr2)                 ++VV;              P[i][var[j].i]=VV;         }     }     for (i=1; i<=n; ++i)         ind[i].i=i, ind[i].poz=P[lg[n]+1][i];      sort (ind+1, ind+n+1, cmp2);      for (i=1; i<=n-K+1; ++i)         sol=max(sol, lca(i, i+K-1));     g<<sol<<"\n";       return 0; }