View Compilation Error

0_0_33804848_17199.cpp:20:15: error: redefinition of 'll f2'
 ll f[MAXN],f2,f2;
               ^
0_0_33804848_17199.cpp:20:12: note: 'll f2' previously declared here
 ll f[MAXN],f2,f2;
            ^
0_0_33804848_17199.cpp: In function 'void init()':
0_0_33804848_17199.cpp:24:2: error: 'f1' was not declared in this scope
  f1 = f2 = 0;
  ^
0_0_33804848_17199.cpp: In function 'void solve()':
0_0_33804848_17199.cpp:38:7: error: 'f1' was not declared in this scope
   if(!f1)f1 = a == 1;
       ^
0_0_33804848_17199.cpp:41:5: error: 'f1' was not declared in this scope
  if(f1 && f2)cout<<"YES"<<endl;
     ^