C++ program to calculate the result of students using marks

#include<iostream>
#include<conio.h>

int main(void)
{

    int comp, phy,math,eng,stat,total;
    float avg;

    std::cout<<"Enter the marks of computer = ";
    std::cin>>comp;
    std::cout<<"Enter the marks of physics = ";
    std::cin>>phy;
    std::cout<<"Enter the marks of mathematics = ";
    std::cin>>math;
    std::cout<<"Enter the marks of english = ";
    std::cin>>eng;
    std::cout<<"Enter the marks of statistics = ";
    std::cin>>stat;

    total = (comp+phy+math+eng+stat);
    avg = ((total/500.0)*100.0);

    std::cout<<"The total marks obtained by student = "<<total <<std::endl;
    std::cout<<"The average of total marks is = "<<avg<<std::endl;

    if(avg >= 85)
        std::cout<<"The grade is A+";
    if(avg >= 75 && avg <= 84)
        std::cout<<"The grade is A";
    if(avg >= 60 && avg <= 74)
        std::cout<<"The grade is B";
    if(avg >= 50 && avg <= 59)
        std::cout<<"The grade is C";
    if(avg < 50)
        std::cout<<"Fail";

    return 0;
}

Enter the marks of computer = 67
Enter the marks of physics = 64
Enter the marks of mathematics = 75
Enter the marks of english = 80
Enter the marks of statistics = 82
The total marks obtained by student = 368
The average of total marks is = 73.599998
The grade is B