import sys
def f(s):
    n = len(s)
    dd = 0
    
    for i in range(n):
        aaa = {}
        bbb = 0
        
        for j in range(i, n):
            char = s[j]
            if char not in aaa:
                aaa[char] = 0
            aaa[char] += 1
            bbb = max(bbb, aaa[char])
            
            ttt = j - i + 1
            
            if bbb <= ttt // 2:
                dd += 1
    
    return dd

s = input().strip()
print(f(s))