CF-811A

A. Vladik and Courtesy

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

At regular competition Vladik and Valera won a and b candies respectively. Vladik offered 1 his candy to Valera. After that Valera gave Vladik 2 his candies, so that no one thought that he was less generous. Vladik for same reason gave 3 candies to Valera in next turn.

More formally, the guys take turns giving each other one candy more than they received in the previous turn.

This continued until the moment when one of them couldn’t give the right amount of candy. Candies, which guys got from each other, they don’t consider as their own. You need to know, who is the first who can’t give the right amount of candy.

Input

Single line of input data contains two space-separated integers a, b (1 ≤ a, b ≤ 109) — number of Vladik and Valera candies respectively.

Output

Pring a single line "Vladik’’ in case, if Vladik first who can’t give right amount of candy, or "Valera’’ otherwise.

Examples

input

1 1

output

Valera

input

7 6

output

Vladik

Note

Illustration for first test case:

Illustration for second test case:

题意：

每次减数递增，求最终谁先小于0

AC代码：

#include<bits/stdc++.h>
using namespace std;

int main(){
    ios::sync_with_stdio(false);
    int a,b;
    cin>>a>>b;
    int ans=0,temp=1;
    while(a>=0&&b>=0){
        if(ans%2==0){
            a-=temp; 
        }
        else{
            b-=temp;
        }
        temp++;
        ans++;
    }
    if(b<0){
        cout<<"Valera"<<endl;
    }
    else{
        cout<<"Vladik"<<endl; 
    }
    return 0;
}