#include<iostream>
#include<stdio.h>
using namespace std;
string s;
int ans,n,tmp;
int main()
{
	scanf("%s",&s);
	for(int i=0;i<s.length();i++)
	{
		if(s[i]<='o'||s[i]>='t'&&s[i]<='v')
		{
			n=(int)s[i];
			if(n-91>3)tmp=91+3;
			ans=ans+n-tmp;
		}
		if(s[i]>='p'&&s[i]<='s'||s[i]>='w')
		{
			n=(int)s[i];
			if(n-91>4)tmp=91+4;
			ans=ans+n-tmp;
		}
		else ans+=1;
	}
	cout<<ans;
	return 0;
}