s = input()
ngs = len(s)
num = 26
dp = [[[0]*2 for i in range(num)] for i in range(ngs+1)]
#dp[0][0] = 1

mod = 10**9+7

for i in range(ngs):
    idx = ord(s[i])-ord("a")
    dp[i+1][idx][0] += 1
    dp[i+1][idx][1] += 1
    #print(dp[i+1])
    for j in range(num):
        if j == idx:
            dp[i+1][idx][0] += dp[i][j][0]*2
            dp[i+1][idx][1] += dp[i][idx][1]*2
            dp[i+1][idx][0] %= mod
            dp[i+1][idx][1] %= mod
        elif dp[i][j][0] != 0:
            dp[i+1][idx][0] += dp[i][j][0]+dp[i][j][1]
            dp[i+1][idx][0] %= mod
            dp[i+1][idx][1] += dp[i][j][1]
            dp[i+1][idx][1] %= mod
            dp[i+1][j][0] = dp[i][j][0]
            dp[i+1][j][0] %= mod
            dp[i+1][j][1] = dp[i][j][1]
            dp[i+1][j][1] %= mod
        #else:
        #    dp[i+1][j] = dp[i][j]
    #print(dp[i+1])

ans = 0
#print(dp)
for i in range(num):
    ans += dp[ngs][i][0]
    ans %= mod

print(ans)