include

include

include

include

//Complete the following function.

int find_nth_term(int n, int a, int b, int c) { //Write your code here. int ret = 0; int d = 0;

if(n == 1)
{
    ret = a;
}
else if(n == 2)
{
    ret = b;
}
else if(n == 3)
{
    ret = c;
}else{
    d = c + b + a;       
    ret = find_nth_term(n - 1, b, c, d);
}

return ret;

}

int main() { int n, a, b, c;

scanf("%d %d %d %d", &n, &a, &b, &c);
int ans = find_nth_term(n, a, b, c);

printf("%d", ans); 
return 0;

}