#define _DE123BUG
// #include <atcoder/all>
#include <bits/stdc++.h>
using namespace std;
// using namespace atcoder;
#define endl "\n"
#define fi first
#define se second
#define all(x) (x).begin(),(x).end() 
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pld;
typedef vector<int> vi;
typedef vector<pii> vii;
const long double pi = acos(-1.0);
const int INF = 1987654331;
const ll LLINF = 1e18;
const double eps = 1e-9;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
////////////////////////

// #ifndef ONLINE_JUDGE
// #include "template.cpp"
// #else
// #define debug(...)
// #define debugArr(...)
// #endif

////////////////////////

int main(){
#ifdef _DEBUG   
    freopen ("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif      
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    
    ll a,b;cin>>a>>b;
    if(a>0)cout<<(a%b)<<endl;
    else cout<<(a%b)+b<<endl;
    
    
    return 0;
}