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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int r = 200, x, y;
    vector<vector<int>> dp(2 * r + 1, vector<int>(2 * r + 1, 1 << 30));
    queue<pair<int,int>> nxt;
    cin >> x >> y;
    dp[x + r][y + r] = 0;
    nxt.emplace(x + r, y + r);
    while(!nxt.empty()){
        tie(x, y) = nxt.front();
        nxt.pop();
        x -= r, y -= r;
        if(dp[x + r][y + r] + 1 < dp[y + r][x + r]){
            dp[y + r][x + r] = dp[x + r][y + r] + 1;
            nxt.emplace(y + r, x + r);
        }
        int v1 = x + y + r, v2 = x - y + r;
        if(v1 >= 0 && v2 >= 0 && v1 < dp.size() && v2 < dp.size() &&
             dp[x + r][y + r] + 1 < dp[x + y + r][x - y + r]){
            dp[x + y + r][x - y + r] = dp[x + r][y + r] + 1;
            nxt.emplace(x + y + r, x - y + r); 
        }
    }
    int ans = 1 << 30;
    for(int i = 0; i < dp.size(); i++) ans = min(ans, dp[i][i]);
    cout << (ans >> 30 & 1 ? -1 : ans) << '\n';
}