View Compilation Error

0_0_20673277_11482.cpp: In function 'int main()':
0_0_20673277_11482.cpp:41:51: error: invalid initialization of reference of type 'int&' from expression of type 'long long int'
     up(ans, cnt[0][i-1][j]*cnt[1][i+1][a[i]^j]%mod);
                                                   ^
0_0_20673277_11482.cpp:9:6: note: in passing argument 1 of 'void up(int&, int)'
 void up(int &u, int v) {u=(u+v)%mod;}
      ^