#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
const int N = 2000086, MOD = 998244353, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];

inline void read(__int128 &X)
{
    X = 0;
    int w=0; char ch=0;
    while(!isdigit(ch)) {w|=ch=='-';ch=getchar();}
    while(isdigit(ch)) X=(X<<3)+(X<<1)+(ch^48),ch=getchar();
    if (w) X = -X;
}


int exgcd(int a, int b, int& x, int& y) {
    if (!b) {
        x = 1, y = 0;
        return a;
    }
    int d = exgcd(b, a % b, y, x);
    y -= a / b * x;
    return d;
}

int main() {
    ll n, b;
    __int128 pn;
    read(pn);
    cin >> b;
    n = pn % b;
    if (__gcd(n, b) != 1) puts("NaN");
    else {
        int x, y;
        exgcd(n, b, x, y);
        ll lcm = b / __gcd(n, b);
        x %= lcm;
        x += lcm;
        x %= lcm;
        printf("%lld\n", x);
    }
    return 0;
}