View Compilation Error

0_0_11110887_19832.cpp:25: error: `main' must return `int'
0_0_11110887_19832.cpp: In function `int main(...)':
0_0_11110887_19832.cpp:27: error: `scanf_s' undeclared (first use this function)
0_0_11110887_19832.cpp:27: error: (Each undeclared identifier is reported only once for each function it appears in.)