View Compilation Error

0_0_25260445_30964.cpp: In function 'int main()':
0_0_25260445_30964.cpp:16:12: error: 'i' was not declared in this scope
         if(i>=a&&a!=1) b*=a;
            ^
0_0_25260445_30964.cpp:17:12: error: 'i' was not declared in this scope
         if(i>=a&&a==1) b*=2;
            ^