0_0_36081753_6241.cpp:3:11: error: '::main' must return 'int' void main() { ^ 0_0_36081753_6241.cpp: In function 'int main()': 0_0_36081753_6241.cpp:12:28: error: 'scanf_s' was not declared in this scope while (scanf_s("%d", &n) != EOF) { ^