【提问】入门自学，帮忙看看这小段程序

看不清楚

完全看不清！！！

@550161091:
#include <iostream>
int main ()
{int sum=0,a=0,b=0,val=a;
std::cout<<"type in two number"<<std::endl;
std::cin>>a>>b;
while (val<=b) { sum += val;
++val;
}
std::cout<<"the inclusive sum from " <<a<< " and " << b <<" is " << sum <<std::endl;
return 0;}