#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <bits/stdc++.h>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    string s;
    cin>>s;
    int q;
    cin>>q;
    
    while(q--)
    {
        int l=0,r=0;
        cin>>l>>r;
        
        l--;
        int rr=r-l+1;
        string news=s.substr(l,rr);
       //cout<<news;
        int count[26]={0};
        
        for(int i=0;i<news.length();i++)
        {
            count[news[i]-'a']++;
        }
        int two=0,one=0;
        for(int i=0;i<26;i++)
        {
            if(count[i]>0)
            {
                if(count[i]%2==0)
                    two++;
                else
                    one++;
            }
        }
        cout<<two+one/2<<endl;
        news.erase();
    }
    
    return 0;
}