#include <cstdio>

#include <cstring>

#include <algorithm>

using namespace std;

const int N=1e6+;

typedef long long ll;

int n;

char s[N],a[N];

int r[N];

void iniStr(char s[]){

    for(int i=;i<=n;i++)

        a[(i<<)-]='#',a[i<<]=s[i]-'';

    a[(n<<)+]='#';

    a[]='@';a[(n<<)+]='$';

}

ll ans;

inline bool cmp(char a,char b){

    return (a=='#'&&b=='#')||((a^b)==);

}

void Manacher(char s[],int n){

    int p=,a;

    for(int i=;i<=n;i++){

        r[i]=i<p?min(p-i+,r[*a-i]):;

        while(cmp(s[i-r[i]],s[i+r[i]])) r[i]++;

        if(i+r[i]->p) p=i+r[i]-,a=i;

        ans+=r[i]>>;

        //printf("r %d %d\n",i,r[i]);

    }

}

int main(){

    freopen("in","r",stdin);

    scanf("%d",&n);

    scanf("%s",s+);

    iniStr(s);

    Manacher(a,n<<|);

    printf("%lld",ans);

}