#include <bits/stdc++.h>
#define ll long long
#define rll register ll
#define cll const ll
#define N 500005
#define M 55
using namespace std;
inline ll read()
{
    rll x=0;bool f=1;register char c=getchar();
    while(c<48||c>57){if(c=='-') f=0;c=getchar();}
    while(c>=48&&c<=57){x=x*10+(c^48);c=getchar();}
    return f?x:-x;
}
inline void write(ll x)
{
    if(x<0) putchar('-'),x=-x;
    if(x>9) write(x/10);
    putchar(x%10+48);
}
ll n,ttt,ans,idx,cntc,idxs=1,last=1,s[N],v[N],h[N],ne[N],sc[N],ch[N],len[N],cnt[M],t[N][M];
bitset<M> flag;
char str[N];
inline ll val(char c)
{
	if(c>=65&&c<=90) return c-65;
	return c-71;
}
inline void insert(ll x)
{
	rll p=++idxs,q,nq;
    len[p]=len[last]+1,s[p]=1;
    while(last&&!t[last][x])
        t[last][x]=p,last=sc[last];
    if(!last)
	{
        sc[p]=1,last=p;
        return;
    }
    q=t[last][x];
    if(len[q]==len[last]+1)
	{
        sc[p]=q,last=p;
        return;
    }
    nq=++idxs;
    len[nq]=len[last]+1;
    sc[nq]=sc[q],sc[q]=sc[p]=nq;
    memcpy(t[nq],t[q],sizeof t[nq]);
    while(t[last][x]==q)
        t[last][x]=nq,last=sc[last];
    last=p;
}
inline void add(ll x,ll y){v[++idx]=y,ne[idx]=h[x],h[x]=idx;}
inline bool check()
{
	for(rll i=2;i<=cntc;i++)
		if(!cnt[ch[i]]||cnt[ch[i]]!=cnt[ch[i-1]])
			return 0;
	return 1;
}
inline void dfs1(ll x)
{
	for(rll i=h[x];~i;i=ne[i])
	{
		cll y=v[i];
		dfs1(y),s[x]+=s[y];
	}
}
inline void dfs2(ll x)
{
	if(check()) ans+=s[x];
	for(rll i=1;i<=cntc;i++)
	{
		cll y=t[x][ch[i]];
		if(y) cnt[ch[i]]++,dfs2(y),cnt[ch[i]]--;
	}
}
int main()
{
	memset(h,-1,sizeof h);
	n=read(),scanf("%s",str+1);
	for(rll i=1,tmp;i<=n;i++)
	{
		tmp=val(str[i]);
		if(!flag[tmp])
			ch[++cntc]=tmp,flag[tmp]=1;
		insert(tmp);
	}
	for(rll i=2;i<=idxs;i++) add(sc[i],i);
	dfs1(1),dfs2(1);
	write(ans);
    return 0;
}