View Compilation Error

0_0_24993103_16419.cpp: In function 'int main()':
0_0_24993103_16419.cpp:42:23: error: 'a' was not declared in this scope
  while(cin>>aa>>bb>>n,a|b|n)
                       ^
0_0_24993103_16419.cpp:42:25: error: 'b' was not declared in this scope
  while(cin>>aa>>bb>>n,a|b|n)
                         ^