CF1834B Maximum Strength

 :::char/strinf 0-1-2-3.....

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<map>
//#include<queue>
//#include<vector>
//#include<bits/stdc++.h>
#define ll long long
#define ddd printf("-----------------------\n");
using namespace std;
const int maxn=1e1 ;

string a,b;

int main()
{
    ios::sync_with_stdio(false);
    int T;cin>>T;
    while(T--)
    {
        cin>>a>>b;
        reverse(a.begin(),a.end()),reverse(b.begin(),b.end());
        while(a.size()<b.size()) a.push_back('0');
        while(a.size()>b.size()) b.push_back('0');
        int len=max(a.size(),b.size())-1;
        while(len>=0&&a[len]==b[len]) len--;
        if(len==-1) cout<<"0\n";
        else cout<<abs((int)(a[len]-b[len]))+len*9<<'\n';//!!!!!
    }
    
    return 0;
}