View Compilation Error

0_0_10213602_24475.cpp:4: error: `main' must return `int'
0_0_10213602_24475.cpp: In function `int main(...)':
0_0_10213602_24475.cpp:8: error: `f' undeclared (first use this function)
0_0_10213602_24475.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_10213602_24475.cpp: In function `int f(long int, int, int)':
0_0_10213602_24475.cpp:11: error: `int f(long int, int, int)' used prior to declaration