siam boss

/*  TAHMID RAHMAN
    DAMIAN FOREVER
     MATH LOVER
    NEVER GIVE UP
*/
#include<bits/stdc++.h>
using namespace std;
#define pi acos(-1.0)
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define ll long long
#define pb push_back
#define fi first
#define se second
#define in insert
#define mp make_pair
#define GCD(a,b) __gcd(a,b);
#define endl "\n"
#define FRU freopen("out.txt","w",stdout)
#define FRO freopen("in.txt","r",stdin)
#define INFLL 9223372036854775807
#define debug 0
#define MAXN   100001
//Don't hesitate to ask me if you don't understand my code.......Happy coding,Tahmid...;

int main()
{
    fastio;
    ll i,c=0,a=0,b=0;
    string s,t;
    cin>>s>>t;
   // s.erase(s.begin());
    //cout<<s<<endl;


        while(1)
        {
            if(s.size()>t.size())
            {
                s.erase(s.begin());
                c++;
            }
            else if(t.size()>s.size())
            {
                t.erase(t.begin());
                c++;
            }
            else if(s.size()==t.size())
            {
              break;
            }
        }

    reverse(s.begin(),s.end());
    reverse(t.begin(),t.end());
    for(i=0;i<s.size();i++)
    {
        if(s[i]==t[i])
        {
              a+=2;
        }
        else
            break;

    }
    b=s.size();
    cout<<c+(2*b)-a;
}