Long Digits Number

#include <bits/stdc++.h>

using namespace std;

#define ll long long

#define rep(i, n) for (ll i = 0; i < n; ++i)

​

int main() {

    ll n,c,x,sum=0,flag=0;

    char d;

    cin>>n;

    if(n<=0||n>100000) cout<<-1<<endl;

    rep(i,n){

        cin>>d>>c;

        if(d>'F'||c<0||c>1000000000) cout<<-1<<endl;

        if(i==0&&d=='0') cout<<-1<<endl;

        if(d>='A'){

            x=10+d-'A';

        }else{

            x=d-'0';

        }

        sum+=x*c;

        sum%=5;

        if(i==n-1&&x%2==1) flag=1;

    }

    if(sum==0&&flag==0) cout<<"Yes"<<endl;

    else cout<<"No"<<endl;

}