#include "bits/stdc++.h"

using namespace std;

string s, t;

int main() {
    ios::sync_with_stdio(false);
    cout.tie(nullptr);
    cin.tie(nullptr);
    cin >> s >> t;
    int i = 0, current = 0, ans = (int) s.size();
    for (char c : t) {
        while (i < s.size() and s[i] > c) {
            ++current;
            ++i;
        }
        if (s[i] < c) {
            ans = min(ans, current);
            break;
        }
        ans = min(ans, current + (int) s.size() - i);
        ++i;
    }
    cout << ans << '\n';
    return 0;
}