error: expected unqualified-id before ‘{’ token

//this is a test program using a string

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
using namespace std;
int main();
{




//tell the user to enter a sentence

cout<< "Please enter a sentence:";

//declare the variable

string USERINPUT;

//define the input

cin>> USERINPUT;

//return the sentence
cout<< "You entered: " USERINPUT endl;

return 0;

}

int main();  // <-- do not put a semi-colon here.
{