1005B. Delete from the Left.cpp

/***

            Bismillahir Rahmanir Rahim
            Read in the name of Allah, who created you!!!
            Author : Shah Newaj Rabbi Shishir,
            Department of CSE, City University, Bangladesh.

***/

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

#define sf scanf
#define pf printf
#define ssf sscanf
#define spf sprintf
#define fsf fscanf
#define fpf fprintf
#define fast ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define scase sf ("%d",&tc)
#define sn sf ("%d",&n)
#define whilecase while (tc--)
#define eof while (cin >> n)
#define forloop for (pos=1; pos<=tc; pos++)
#define arrayloop (i=0; i<n; i++)
#define cinstr cin >> str
#define getstr getline (cin,str)
#define pcase pf ("Case %d: ",pos)
#define vi vector <int>
#define pii pair <int,int>
#define mii map <int,int>
#define pb push_back
#define in insert
#define llu unsigned long long
#define lld long long
#define U unsigned int
#define endl "\n"

const int MOD = 1000000007;
const int MAX = 1000005;

int SetBit (int n, int x) { return n | (1 << x); }
int ClearBit (int n, int x) { return n & ~(1 << x); }
int ToggleBit (int n, int x) { return n ^ (1 << x); }
bool CheckBit (int n, int x) { return (bool)(n & (1 << x)); }

char a[200005],b[200005];

int main (void)
{
    /*
    freopen ("input.txt","r",stdin);
    freopen ("output.txt","w",stdout);
    */

    int i,j,len,l1,l2,ans;

    while (sf ("%s %s",a,b) != EOF)
    {
        l1 = strlen(a);
        l2 = strlen(b);

        ans = 0;

        for (i=l1-1,j=l2-1; i>=0,j>=0; i--,j--)
            if (a[i] != b[j])
                break;

        if (i != -1)
            ans += (i+1);
        if (j != -1)
            ans += (j+1);

        pf ("%d\n",ans);
    }

    return 0;
}