View Compilation Error

0_0_30193435_701.cpp: In function 'node cck(ll, ll, ll, ll)':
0_0_30193435_701.cpp:30:25: error: invalid initialization of reference of type 'll& {aka long long int&}' from expression of type '__int128'
     LL gcd=exgcd(m,n,x,y);
                         ^
0_0_30193435_701.cpp:11:4: note: in passing argument 3 of 'll exgcd(ll, ll, ll&, ll&)'
 ll exgcd(ll a,ll b,ll &x,ll &y){
    ^