View Compilation Error

0_0_26728720_20878.cpp: In function 'int main()':
0_0_26728720_20878.cpp:7:17: error: 'o' was not declared in this scope
         if(n%2==o);
                 ^
0_0_26728720_20878.cpp:11:9: error: 'else' without a previous 'if'
         else
         ^
0_0_26728720_20878.cpp:17:12: error: 'o' was not declared in this scope
     return o;
            ^