Using getline(cin.input) to input a string in a while loop - c++

Question

Currently working on the following homework problem:
Enter destination city, miles traveled to get there and gallons of gasoline used for any number of trips entered at the keyboard (use ctl+z to stop). Use a function to compute miles per gallon(miles traveled/gallons used). Display the destination city and miles per gallon for each trip entered. Sum the miles traveled and give a count of the number of trips made. Display these at the end of the program.
The problem occurs during the second iteration of the while loop.
When asking the using for input, the output "Enter destination city, ctrl+z to stop:" and 'Enter miles to destination and gallons of gasoline needed, ctrl+z to stop:" are merged into one output.
In other words, the console does not allow the user time to input a city after asking for a destination the second time. Instead, both outputs are displayed back to back and whatever is input is stored into gallons and gasoline resulting in an error.
I have tried adding more likes between the code.
I tried adding a system("pause") between the lines.
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
float mpgFunc(float, float);
int main()
{
//variable declaration
string destination;
float milesToDest, gasolineNeeded, MPG, totalMiles = 0.0f;
int count = 0;
//input phase
cout << "Enter destination city, ctrl+z to stop: " << endl;
getline(cin, destination);
cout << "Enter miles to destination and gallons of gasoline needed,
ctrl+z to stop: " << endl;
cin >> milesToDest >> gasolineNeeded;
while (!cin.eof())
{
MPG = mpgFunc(milesToDest, gasolineNeeded); //function call
count = count + 1; //counter
totalMiles = totalMiles + milesToDest; //sum
cout << setprecision(2) << fixed;
cout << "Destination city: " << setw(10) << destination <<
endl;
cout << "Miles per gallon: " << setw(10) << MPG << endl;
/* Problem
cout << "Enter destination city, ctrl+z to stop: " << endl <<
endl;
getline(cin, destination);
cout << "Enter miles to destination and gallons of gasoline
needed, ctrl+z to stop: " << endl;
cin >> milesToDest >> gasolineNeeded;
problem happens here the two outputs are merged into one output */
}
cout << endl;
cout << "Total miles traveled: " << setw(8) << totalMiles << endl;
cout << "Total trips taken: " << setw(8) << count << endl;
system("pause");
return 0;
}//end main
float mpgFunc(float milesToDest, float gasolineNeeded)
{
float MPG;
MPG = milesToDest / gasolineNeeded;
return MPG;
}