#include<bits/stdc++.h>
using namespace std;

#define rep(i, n) for(int (i) = 0; (i) < (n); (i)++)
#define repp(i, n, m) for(int (i) = (n); (i) < (m); (i)++)
#define repn(i, n) for(int (i) = 1; (i) <= (n); (i)++)
#define repr(i, n) for(int (i) = (n-1); (i) >= 0; (i)--)
#define all(x) (x).begin(), (x).end()
#define lint long long
#define ulint unsigned long long
#define ldou long double
#define fi first
#define se second
#define setpre(x) std::cout << fixed << setprecision(x)
#define ii(x) int x; cin >> (x)
#define ii2(x, y) int x, y; cin >> (x) >> (y)
#define ii3(x, y, z) int x, y, z; cin >> (x) >> (y) >> (z)
#define out(x) cout << (x) << endl
#define outs(x) cout << (x) << " "
#define yn(x) cout << ((x)?("Yes"):("No")) << endl
#define YN(x) cout << ((x)?("YES"):("NO")) << endl
#define bit_c(x) __builtin_popcountll(x)

inline void logger(){ std::cout << " [LOGGER] " << endl; }
template<typename A, typename... B>
void logger(const A& a, const B&... b){
    cout << a << " , "; logger(b...);
}

typedef pair<lint, lint> P;
const lint MOD = 1000000007;
const lint MOD9 = 998244353;
const lint INF = MOD * MOD;
const int MAX = 200005;

/* ...o(^-^)o... */

int main(){
    int a, b, ans; cin >> a >> b;
    ans = 0;

    repp(i, a, b+1){
        string s = to_string(i); int l = s.length();
        bool f = true;
        rep(j, l){
            if(s[j] != s[l-1-j]) f = false;
        }
        if(f) ans++;
    }

    out(ans);
}
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
using namespace __gnu_pbds;
using namespace std;
typedef tree<
    pair<int, int>,
    null_type,
    less_equal<pair<int, int>>,
    rb_tree_tag,
    tree_order_statistics_node_update>
    ordered_set;
#define int long long
#define double long double
#define all(a) (a).begin(), (a).end()
#define x first
#define y second
#define lb(v, z) lower_bound(all(v), z)
#define ub(v, z) upper_bound(all(v), z)
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define rdp(i, a, b) for (int i = (a); i >= (b); i--)
#define rlt(i, a, b) for (int i = (a); i < (b); i++)
#define cns(z) cout << (z) << ' '
#define cnl(z) cout << (z) << '\n'
#define M1 1000000007
#define M2 998244353
#define MAXN 300005
#define INF (1ll << 60)
#define endl "\n"
#define garr(ip)       \
    for (auto &x : ip) \
        cin >> x;
#define parr(ip)          \
    for (auto &x : ip)    \
        cout << x << " "; \
    cout << endl;
#define nl cout << endl
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pair<int, int>> vp;

void solve(int testCaseNumber = 1)
{
    int n;
    cin >> n;
    string ans;
    while (n > 0)
    {
        n--;
        ans += 'a' + n % 26;
        n /= 26;
    }
    reverse(all(ans));
    cnl(ans);
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    solve();
}