View Compilation Error

0_0_21711063_23666.cpp: In function 'void dfs(int, int)':
0_0_21711063_23666.cpp:27:31: error: invalid initialization of reference of type 'long long int&' from expression of type 'long long unsigned int'
        calc(a[f1][!z1&&!z2||z1],f[u][m1][z1],f[v][m2][z2],m2&15);
                               ^
0_0_21711063_23666.cpp:9:13: note: in passing argument 1 of 'void calc(long long int&, long long int&, long long int&, int)'
 inline void calc(long long &x,long long &y,long long &z,int yep){
             ^
0_0_21711063_23666.cpp:28:21: error: invalid initialization of reference of type 'long long int&' from expression of type 'long long unsigned int'
        calc(a[f2][z1],f[u][m1][z1],f[v][m2][z2],m2&15);
                     ^
0_0_21711063_23666.cpp:9:13: note: in passing argument 1 of 'void calc(long long int&, long long int&, long long int&, int)'
 inline void calc(long long &x,long long &y,long long &z,int yep){
             ^