View Compilation Error

0_0_29849503_20183.cpp: In function 'int Calc(int, __int128, __int128)':
0_0_29849503_20183.cpp:75:47: error: invalid initialization of reference of type 'long long int&' from expression of type 'int'
             add(res,((R/d-L/d)%mod*phi[d]%mod));
                                               ^
0_0_29849503_20183.cpp:36:6: note: in passing argument 1 of 'void add(long long int&, long long int)'
 void add(long long &a, long long b){
      ^
0_0_29849503_20183.cpp:77:61: error: invalid initialization of reference of type 'long long int&' from expression of type 'int'
                 add(res,((R/(a/d)-L/(a/d))%mod*phi[a/d]%mod));
                                                             ^
0_0_29849503_20183.cpp:36:6: note: in passing argument 1 of 'void add(long long int&, long long int)'
 void add(long long &a, long long b){
      ^