View Compilation Error

0_0_27590182_17559.cpp: In function 'int main()':
0_0_27590182_17559.cpp:26:27: error: 'getf' was not declared in this scope
          if(a==-1)a=getf(i);
                           ^
0_0_27590182_17559.cpp:27:22: error: 'getf' was not declared in this scope
          if(a!=getf(i))flag=false;
                      ^