求调

#include <bits/stdc++.h>
#define int long long
using namespace std;
string s;
int dp[2000005];
int g[200005];
int ans;
signed main(){
	ios::sync_with_stdio();
	cin.tie(0);
	int n;
	cin>>n>>s;
	s=" "+s;
	for(int i=1;i<=n;i++){
		int k=i-1;
		while(k>0&&s[i]!=s[k]){
			k=g[k]-1;
		}
		if(k<=0){
			continue;
		}
		g[i]=k;
		dp[i]=dp[k-1]+1;
		ans+=dp[i];
		//cout<<i<<" "<<dp[i]<<"\n";
	}
	cout<<ans;
}