const MOD: usize = 1e9 as usize + 7;

fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let s = s.trim().chars().map(|c| c as usize - 'a' as usize).collect::<Vec<_>>();

    let n = s.len();
    let mut dp = vec![vec![0usize; 27]; n+1];
    let mut valdp = vec![vec![0usize; 27]; n+1];
    dp[0][26] = 1;
    for i in 0..n {
        for j in 0..=26 {
            if dp[i][j] == 0 { continue; }
            dp[i+1][j] += dp[i][j];
            dp[i+1][s[i]] += dp[i][j];
            dp[i+1][s[i]] %= MOD;

            valdp[i+1][j] += valdp[i][j];
            valdp[i+1][j] %= MOD;
            valdp[i+1][s[i]] += valdp[i][j];
            if s[i] != j {
                valdp[i+1][s[i]] += dp[i][j];
            }
            valdp[i+1][s[i]] %= MOD;
        }
    }
    println!("{}", valdp[n].iter().take(26).sum::<usize>() % MOD);
}