#include<iostream>

#include<cstring>

#include<cstdlib>

#include<cstdio>

using namespace std;

char s[];

int dp[][],a[];

int dfs(int pos,int pre,bool lead,bool limit)

{

    if(pos==)

    if(lead)return ;else return ;

    if(!limit && dp[pos][pre]!=-)return dp[pos][pre];

    int up=limit?a[pos]:;

    int ans=,i;

    if(lead)i=pre;else i=pre+;

    for(;i<=up;i++)

    ans+=dfs(pos-,i,lead && i==,limit && i==a[pos]);

    if(!limit)dp[pos][pre]=ans;

    return ans;

}

int solve()

{

    int pos=;

    for(int i=;i<strlen(s)-;i++)

    if(s[i]>=s[i+])return ;

    for(int i=strlen(s)-;i>=;i--)

    a[++pos]=s[i]-'a'+;

    return dfs(pos,,,);

}

int main()

{

    memset(dp,-,sizeof(dp));

    scanf("%s",s);

    printf("%d\n",solve());

}