ll x,y,a,b;
void exgcd(ll a, ll b)
{
if(b==0)
{
x=1;
y=0;
return ;
}
exgcd(b,a%b);
ll t=x;
x=y;
y=t-a/b*y;
return ;
}
ll x,y,a,b;
void exgcd(ll a, ll b)
{
if(b==0)
{
x=1;
y=0;
return ;
}
exgcd(b,a%b);
ll t=x;
x=y;
y=t-a/b*y;
return ;
}