#include <iostream>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <set>
#include <algorithm>
#include <bitset>
#include <time.h>
#include <tuple>
#include <fstream>
#include <iomanip>
#include <utility>

#pragma warning "da 100% din tine. :)"
#define nl '\n'
#define sp ' '
#define pb(x) push_back(x)
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define SIZE 3000
#define NR 105
#define N 11
#define INF 10000

using namespace std;

int gcd(int a, int b){
    if(a==0)
        return b;
    if(b==0)
        return a;
    return gcd(b, a % b);
}

int main() {
    freopen("cmmdc.in", "r", stdin);
    freopen("cmmdc.out", "w", stdout);
    ios_base::sync_with_stdio(false);
//    clock_t tStart = clock();
    int a, b;
    cin >> a >> b;
    if(gcd(a,b)==1)
        cout << 0;
    else cout << gcd(a,b);

//    printf("\nTime taken: %.2fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
}