// Source: https://usaco.guide/general/io

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

signed main() {
    int n,c;cin>>n>>c;
    vector<int> v(n);
    for(int i = 0;i<n;i++){
        cin>>v[i];
    }
    vector<int> last(c),volte(c);
    set<pair<int,int>> s;
    int volt=0,ans=n;
    for(int i = 0;i<n;i++){
        int C=v[i];
        s.erase({last[C],C});
        if(volte[C]==0){
            volt++;
            volte[C]=1;
        }
        last[C]=i;
        s.insert({last[C],C});
        if(volt==c){
            auto [ind,szin]=*s.begin();
            ans=min(ans,i-ind+1);
        }
    }
    cout<<ans<<endl;
}