View Compilation Error

0_0_23523251_19424.cpp: In function 'int main()':
0_0_23523251_19424.cpp:11:3: error: expected ';' before 'a'
   a=0,b=0;
   ^
0_0_23523251_19424.cpp:13:4: error: 'cin' was not declared in this scope
    cin>>ai[i];
    ^