View Compilation Error

0_0_27074570_32364.cpp: In function 'int main()':
0_0_27074570_32364.cpp:3:15: error: expected initializer before '==' token
 {int x,y,z,sum==0,a;
               ^
0_0_27074570_32364.cpp:8:12: error: 'a' was not declared in this scope
     case 1:a=0;break;
            ^
0_0_27074570_32364.cpp:25:12: error: 'a' was not declared in this scope
     case 1:a=0;break;
            ^
0_0_27074570_32364.cpp:40:17: error: 'a' was not declared in this scope
   printf("%d\n",a+z);
                 ^