#!/bin/python3

import sys
from collections import Counter
debug = False

def initialize(s):
    # This function is called once before all queries.
    pass

def answerQuery(l, r):
    # Return the answer for this query modulo 1000000007.
    # 10**9 + 7
    word = s[l-1:r]
    c = Counter(word)
    total = 0
    for k, v in c.items():
        if v % 2 == 1:
            v -= 1
        total += v
    total /= 2
    if 1 in c.values():
        total += 1
    return int(total)

if __name__ == "__main__":
    s = input().strip() if not debug else 'abab'
    initialize(s)
    q = int(input().strip()) if not debug else 1
    for a0 in range(q):
        l, r = input().strip().split(' ') if not debug else (1,4)
        l, r = [int(l), int(r)]
        result = answerQuery(l, r)
        print(result)