Little Elephant and Interval

TF. Little Elephant and Interval

The Little Elephant very much loves sums on intervals.

This time he has a pair of integers l and r (l ≤ r). The Little Elephant has to find the number of such integers x (l ≤ x ≤ r), that the first digit of integer x equals the last one (in decimal notation). For example, such numbers as 101, 477474 or 9 will be included in the answer and 47, 253 or 1020 will not.

Help him and count the number of described numbers x for a given pair l and r.

Input

The single line contains a pair of integers l and r (1 ≤ l ≤ r ≤ 1018) — the boundaries of the interval.

Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specifier.

Output

On a single line print a single integer — the answer to the problem.

Example

Input

2 47

Output

12

Note

In the first sample the answer includes integers 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44.

code

#include<bits/stdc++.h>
#define int long long
#define endl '\n'
 
using namespace std;


const int N = 510,INF=0x3f3f3f3f,mod=1e9+7;
 
typedef pair<int,int> PII;

int T=1;

int f(int x){
	if(x<10) return x;
	string str=to_string(x);
	if(str[0]>str[str.size()-1]) return x/10+8;
	else return x/10+9;
}

void solve(){
	int n,m;
	cin>>n>>m;
	cout<<f(m)-f(n-1)<<endl;
}

signed main(){
//	cin>>T; 
    while(T--){
        solve();
    }
    return 0;
}