View Compilation Error

372700_0_0_2139.cpp:2: error: `main' must return `int'
372700_0_0_2139.cpp: In function `int main(...)':
372700_0_0_2139.cpp:7: error: `sanf' undeclared (first use this function)
372700_0_0_2139.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)