C++ :

#include<iostream>
using namespace std;
int main()
{
    int a,sum;
	while(a!=-1)
	{
	    cin>>a;
	    sum+=a;
	}
	cout<<sum-4195823;
	return 0;
} 

Python :

# coding=utf-8
a=int(input())
s=0
while(a!=-1):
    s+=a
    a=int(input())
print(s)