#include <iostream>
using namespace std;

bool Check(const string& slong, const string& sshort) {
    int n = sshort.size();
    int idx = 0;
    while (idx < n && sshort[idx] == slong[idx]) {
        idx++;
    }
    while (idx < n && sshort[idx] == slong[idx + 1]) {
        idx++;
    }
    return idx == n;
}

bool OneEditApart(const string& s1, const string& s2) {
    if (s1.size() == s2.size()) {
        int left_difference_idx = 0;
        while (left_difference_idx < s1.size() && s1[left_difference_idx] == s2[left_difference_idx]) {
            left_difference_idx++;
        }

        int right_difference_idx = s1.size() - 1;
        while (right_difference_idx >= 0 && s1[right_difference_idx] == s2[right_difference_idx]) {
            right_difference_idx--;
        }

        if (left_difference_idx == s1.size()) {
            return false;
        }

        return left_difference_idx == right_difference_idx;
    } else if (s1.size() == s2.size() + 1){
        return Check(s1, s2);
    } else if (s2.size() == s1.size() + 1){
        return Check(s2, s1);
    }

    return false;
}

int main() {
    cout << OneEditApart("cat", "cat") << endl;
    cout << OneEditApart("#", "") << endl;
    cout << OneEditApart("", "#") << endl;
    cout << OneEditApart("123", "1234") << endl;
    cout << OneEditApart("cat", "at") << endl;
    cout << OneEditApart("cat", "cut") << endl;
    cout << OneEditApart("12errjfasjlf", "cdfdfdut") << endl;
    cout << OneEditApart("", "cdfdfdut") << endl;

    return 0;
}