const MOD: usize = 1e9 as usize + 7;
const SIZE: usize = 26;

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 cntdp = vec![vec![0usize; SIZE+1]; n+1];
    let mut valdp = vec![vec![0usize; SIZE+1]; n+1];
    cntdp[0][SIZE] = 1;
    for i in 0..n {
        for j in 0..=SIZE {
            if cntdp[i][j] == 0 { continue; }
            cntdp[i+1][j] += cntdp[i][j];
            cntdp[i+1][j] %= MOD;
            cntdp[i+1][s[i]] += cntdp[i][j];
            cntdp[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 j != s[i] { cntdp[i][j] } else { 0 };
            valdp[i+1][s[i]] %= MOD;
        }
    }
    println!("{}", valdp[n].iter().take(SIZE).sum::<usize>() % MOD);
}