显示代码纯文本
#include<bits/stdc++.h>
#define int long long
#define re register
#define il inline
#define inf 1e18
#define eps 1e-15
#define ll unsigned long long
#define mod 998244353
#define bianli for(int i=head[x];i;i=a[i].next)
#define QWQ cout<<"qwq";
#define me(qw) memset(qw,0,sizeof(qw));
#define meinf(qw) memset(qw,0x3f,sizeof(qw));
using namespace std;
const int maxn=1e5+5;
int x, y;
void ex(int a,int b){
if(b==0){
x=1;y=0;
return;}
ex(b,a%b);
int tmp=x;
x=y;
y=tmp-a/b*y;
}
signed main(){
freopen("mod.in","r",stdin);
freopen("mod.out","w",stdout);
int a,b;
cin>>a>>b;
ex(a,b);
x+=b;
cout<<x%b;
return 0;
}