View Compilation Error

0_0_26125844_21833.cpp: In function 'int main()':
0_0_26125844_21833.cpp:21:16: error: 'a' was not declared in this scope
    int ni = pi;a
                ^
0_0_26125844_21833.cpp:27:5: error: 'sum' was not declared in this scope
     sum --;
     ^
0_0_26125844_21833.cpp:29:13: error: 'sum' was not declared in this scope
    pl[pi] = sum;
             ^