#!/bin/python3

import sys

def answerQuery(b):
    # Return the answer for this query modulo 1000000007.
    sum=0
    cnt=0
    a=[0]*26
    for i in b:
        a[ord(i)-97]+=1
    for i in a:
        if(i %2==0):
            sum+=i//2
        elif(i==1):
            cnt+=1
    #print(a,sum,cnt)
    if(cnt>1):   
        return sum+cnt-1
    return sum

if __name__ == "__main__":
    s = input().strip()
    q = int(input().strip())
    for a0 in range(q):
        l, r = input().strip().split(' ')
        l, r = [int(l), int(r)]
        result = answerQuery(s[l-1:r])
        print(result)