View Compilation Error

92781_0_23243.cpp:4: error: `main' must return `int'
92781_0_23243.cpp: In function `int main(...)':
92781_0_23243.cpp:6: error: `cout' undeclared (first use this function)
92781_0_23243.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
92781_0_23243.cpp:7: error: `cin' undeclared (first use this function)
92781_0_23243.cpp:10: error: `V' undeclared (first use this function)
92781_0_23243.cpp: In function `float V()':
92781_0_23243.cpp:14: error: `float V()' used prior to declaration