View Compilation Error

0_0_36087712_16155.cpp:2:11: error: '::main' must return 'int'
 void main() {
           ^
0_0_36087712_16155.cpp: In function 'int main()':
0_0_36087712_16155.cpp:13:28: error: 'scanf_s' was not declared in this scope
     while (scanf_s("%d", &j) != EOF && j != -1) {
                            ^