View Compilation Error

0_0_37278290_10130.cpp: In function 'int main()':
0_0_37278290_10130.cpp:10:10: error: 'a' was not declared in this scope
 ; while (a!=0&&b!=0)
          ^
0_0_37278290_10130.cpp:10:16: error: 'b' was not declared in this scope
 ; while (a!=0&&b!=0)
                ^
0_0_37278290_10130.cpp:15:2: error: 'n' was not declared in this scope
  n = n - 1;
  ^