View Compilation Error

0_0_29534031_29471.cpp: In function 'void exgcd(int, int, int&, int&)':
0_0_29534031_29471.cpp:32:14: error: 'm' was not declared in this scope
     y -= a / m * x;
              ^
0_0_29534031_29471.cpp: In function 'int main()':
0_0_29534031_29471.cpp:51:31: error: invalid initialization of reference of type 'int&' from expression of type 'll {aka long long int}'
         exgcd(2 * n, MOD, x, y);
                               ^
0_0_29534031_29471.cpp:25:6: note: in passing argument 3 of 'void exgcd(int, int, int&, int&)'
 void exgcd(int a, int b, int &x, int &y) {
      ^