#include <bits/stdc++.h> #define int long long #define debug cout << "ok\n"; #define SQR(x) (1LL * ((x) * (x))) #define MASK(i) (1LL << (i)) #define BIT(x, i) (((x) >> (i)) & 1) #define fi first #define se second #define pb push_back #define mp make_pair #define pii pair<int,int> #define pli pair<ll,int> #define vi vector<int> #define FAST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); typedef long long ll; typedef unsigned long long ull; typedef long double ld; typedef unsigned int ui; using namespace std; const int M = 1e9 + 7; const int INF = 1e9 + 7; const ll INFLL = (ll)2e18 + 7LL; const ld PI = acos(-1); const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1}; const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1}; template<class _, class __> bool minimize(_ &x, const __ y){ if(x > y){ x = y; return true; } else return false; } template<class _, class __> bool maximize(_ &x, const __ y){ if(x < y){ x = y; return true; } else return false; } template<class _,class __> void Add(_ &x, const __ y) { x += y; if (x >= M) { x -= M; } return; } template<class _,class __> void Diff(_ &x, const __ y) { x -= y; if (x < 0) { x += M; } return; } //-------------------------------------------------------------- const int MaxN = 1e6+7; int n,K,nxt[MaxN][3],res = INF,a[MaxN]; void sol() { cin >> n >> K; for (int i=1;i<=n;i++) { char x; cin >> x; if (x == 'J') a[i] = 0; else if (x == 'O') a[i] = 1; else a[i] = 2; } for (int i=0;i<3;i++) { int cnt = 0; for (int j=n,k=n+1;j>=1;j--) { cnt += a[j] == i; while (cnt >= K) { k--; cnt -= a[k] == i; } nxt[j][i] = k; } } for (int i=1;i<=n;i++) { if (nxt[i][0] < n) { if (nxt[nxt[i][0]+1][1] < n) { if (nxt[nxt[nxt[i][0]+1][1]+1][2] <= n) { minimize(res,nxt[nxt[nxt[i][0]+1][1]+1][2] - i + 1 - 3 * K); } } } } if (res < INF) cout << res; else cout << -1; } signed main() { // freopen("test.inp","r",stdin); // freopen("test.out","w",stdout); FAST int t=1; // cin >> t; while (t--) sol(); }