const MOD: usize = 1_000_000_007;

fn main() {
    let s: Vec<char> = {
        let mut buf = String::new();
        std::io::stdin().read_line(&mut buf).unwrap();
        buf.trim_end().chars().collect()
    };

    let mut ans = 0;
    let mut p = 1;
    let mut dp = vec![0; 27];
    for c in s {
        let i = c as usize - 'a' as usize;
        ans = (ans * 2 + p + MOD - dp[i]) % MOD;
        dp[i] = (dp[i] + p) % MOD;
        p = p * 2 % MOD;
    }
    println!("{}", ans);
}