why re T_T

#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read()
{
    int x=0,F=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')
            F=-1;
        ch=getchar();
    }
    while(ch>='0' && ch<='9')
        x=x*10+ch-'0',ch=getchar();
    return x*F;
}
void write(int x)
{
    if(x<0)
        putchar('-'),x=-x;
    if(x>9)
        write(x/10);
    putchar(x%10+'0');
    return;
}
const int N=1E5+5;
int swlen(int n)
{
	int s=0;
	while(n)
		n/=10, ++s;
	return s;
}
int a[N], b[N], powten[20], n, ans, l, r;
signed main(){
	//泥嚎，写题吧骚年
	powten[0]=1; for(int i=1; i<=18; ++i)powten[i] = powten[i-1]*10;
	n=read();
	for(int i=1; i<=n; ++i)
	a[i]=read();
	for(int i=1; i<=n; ++i)
	b[i]=read();
	stable_sort(b+1, b+n+1);
	for(int i=1; i<=n; ++i)
	{
		int ch=swlen(a[i]);
		while(1)
		{
			l=powten[ch-1]-a[i], r=powten[ch]-a[i];
			if(l>b[n])
			break;
			l=lower_bound(b+1, b+n+1, l)-b, r=lower_bound(b+1, b+n+1, r)-b;
			ans+=ch*(r-l), ++ch;
		}
	}
	write(ans);
	return 0;
}