Can somebody tell me whats is the error?

after if
{.....
C:\Documents and Settings\ashida\My Documents\MASTER C++\main\412.cpp(67) : error C2106: '=' : left operand must be l-value


Code:
#include <iostream>   // std::cout
#include <fstream>
#include <iomanip>
#include <string>    // std::string
#include <vector>    // std::vector<>
#include <algorithm> //std::for each()
using namespace std; // import "std" namespace into global namespace

struct exam
{
int examid;
vector <int> total;
};

void SwapMembers (int items[], int index1, int index2)
{
	int temp;
	temp=items[index1];
	items[index1]=items[index2];
	items[index2]=temp;
}

	int main() 
	{
	ifstream stream1("STA83SOLUTION.txt");
		if ( !stream1.is_open())
		{
		cout << "While opening a file an error is encountered" << endl;
		} 
			else 
			{
			cout << "Fail Di buka....." << endl;
			}
	vector <exam> exams;
	exam aExam;
   int tempExamID;
    int tempTotal;
    stream1 >> tempExamID >> tempTotal;
    aExam.examid = tempExamID;
    aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    while (stream1 >> tempExamID >> tempTotal)
    {
        if(tempExamID != aExam.examid)
        {
        exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
        aExam.total.clear();
        aExam.examid = tempExamID;
        }
        aExam.total.push_back(tempTotal); // add this exam code to current student's vector of exam codes
    }
    exams.push_back(aExam); // no more exam codes for this student.  Add aStudent to students vector
    stream1.close(); // We have read the entire file, so time to close it.
{
	ofstream myfile;
	myfile.open("411.txt");
	
	int temp, flag;
	if (myfile.is_open())
	{
		for (size_t i = 0; i < exams.size(); i++) 
		{
			for (size_t j = 0; j<exams.at(i).total.size(); j++) 
			{
				if (exams.at(i).total.size() < exams.at(i).total.size()+1)      // ascending order simply changes to <
				{ 
                    temp = exams.at(i).total.size();             // swap elements
                    exams.at(i).total.size() = exams.at(i).total.size()+1;
                    exams.at(i).total.size()+1 = temp;
                    flag = 1;               // indicates that a swap occurred.
                }

		cout<<"\n"<<i+1<<":"<<" "<< exams.at (i).total.at(j)<<"\t"; // output list of exam codes for this student
	  	cout<<" "<< exams.at (i).total.at(j)<<"\t";
			}
		}
	}
					
cin.get();
return 0;
}
}