Codeforces Round #496 (Div. 3) B.Delete from the Left(思维)

#include <iostream>
using namespace std;
string str,ch;

int main()
{
	cin>>str>>ch;
	int l1 = str.length();
	int l2 = ch.length();
	int l = l1-1,r=l2-1;
	if(str[l] != ch[r]){
		cout<<l1 + l2 <<endl;
		return 0;
	}

	while(l >= 0 && l >= 0){
		if(str[l] == ch[r]){
			l--;
			r--;
		}
		else{
			break;
		}
	}
	cout<<l + r + 2<<endl;
	return 0;
}