#include #define PB push_back #define MP make_pair #define REP(i,n) for (int i=0;i<(n);i++) #define FOR(i,a,b) for(int i=(a);i<(b);i++) #define ALL(a) (a).begin(),(a).end() using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair P; const int INF=1e9; int main(){ int n; string s; cin>>n>>s; REP(i,n-1){ if(s[i]==s[i+1]){ cout<<"YES"<=4)cout<<"YES"<