s = input().strip()
n = len(s)
mod = 10**9+7
dp = [[0]*26 for _ in range(n+1)]
dp2 = [[0]*26 for _ in range(n+1)]
for i in range(n):
    ci = ord(s[i])-97
    for j in range(26):
        dp[i+1][j] = dp[i][j]
        dp2[i+1][j] = dp2[i][j]
    dp[i+1][ci]+=1
    dp2[i+1][ci]+=1
    for j in range(26):
        dp[i+1][ci] = (dp[i+1][ci] + dp[i][j])%mod
        if j == ci:
            dp2[i+1][ci] = (dp2[i+1][ci] + dp2[i][j])%mod
        else:
            dp2[i+1][ci] = (dp2[i+1][ci] + dp2[i][j] + dp[i][j])%mod
#print(dp[-1])
#print(dp2[-1])
print(sum(dp2[-1])%mod)