View Compilation Error

0_0_19979325_28019.cpp: In function 'int main()':
0_0_19979325_28019.cpp:85:30: error: 'a' was not declared in this scope
       if(op==1) update(1,1,n,a,b);
                              ^
0_0_19979325_28019.cpp:85:32: error: 'b' was not declared in this scope
       if(op==1) update(1,1,n,a,b);
                                ^
0_0_19979325_28019.cpp:88:30: error: 'a' was not declared in this scope
         node ans=query(1,1,n,a,b);
                              ^
0_0_19979325_28019.cpp:88:32: error: 'b' was not declared in this scope
         node ans=query(1,1,n,a,b);
                                ^