#ifdef __AVX2__ #pragma GCC target "avx2" #endif #pragma GCC optimize "O3" #pragma GCC optimize "unroll-loops" #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace __gnu_pbds; using namespace std; #define int long long #define elif else if #define all(l) begin(l),end(l) #define rall(l) rbegin(l),rend(l) #define append push_back #define print(l) for(auto i:l) cout<<i<<' '; cout<<endl; #define pprint(a,b) cout<<a<<' '<<b<<endl; #define inp(l) for(auto &i:l) cin>>i; #define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> #define pai make_pair #define endl "\n" #define pii pair<int,int> #define fi first #define se second #define vec vector // const int mod=998244353; const int mod1=998244353; const int mod=1e9+7; const int N=2e5+5; int iter=1,itera=1; void solve(){ int n,k; cin>>n>>k; string s; cin>>s; s='.'+s; vec<int>J(n+1,-1e18),O(n+1,0),I(n+1,0); deque<int>j1,o1,i1; for(int i=1;i<=n;i++){ if(s[i]=='J'){ j1.append(i); if(j1.size()>k) j1.pop_front(); } elif(s[i]=='O'){ o1.append(i); if(o1.size()>k) o1.pop_front(); } else{ i1.append(i); if(i1.size()>k) i1.pop_front(); } if(j1.size()==k) J[i]=j1[0]; if(o1.size()==k) O[i]=o1[0]; if(i1.size()==k) I[i]=i1[0]; } int ans=1e18; for(int i=1;i<=n;i++){ int l=J[O[I[i]]]; ans=min(ans,(i-l+1)-3*k); } if(ans>n) cout<<"-1\n"; else cout<<ans<<endl; } signed main(){ // freopen("","r",stdin); // freopen("","w",stdout); ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cout<<fixed<<setprecision(20); // cin>>itera; for(iter=1;iter<=itera;iter++) solve(); }