UVA 10170 - The Hotel with Infinite Rooms

/***
Md. Nazmul Hasan
Shahjalal University of Science & Technology,Sylhet.
hasan08sust@gmail.com
***/
#include<iostream>
#include<cstdio>
#include<stack>
#include<queue>
#include<map>
#include<vector>
#include<algorithm>
#include<cstring>
#include<sstream>
#include<cmath>
#include <iomanip>
using namespace std ;
typedef long long ll ;
typedef int in ;
typedef unsigned long long ull ;
const double pi = 2*acos(0) ;
#define maxi 40000
#define pf printf
#define sc scanf
#define pb push_back
#define MEM(x,y) (memset((x),(y),sizeof(x)))
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#define MAX(x,y) ((x) > (y) ? (x) : (y))
#define load(array,size)  for(int i=0 ; i<size ; i++) cin>>array[i]  ;
#define new_line  pf("\n")
#define clear_data(array) memset(array,0,sizeof(array))
#define highest_int 2147483647


int main()
{
    long long s, d;
    while(scanf("%lld %lld", &s, &d) == 2)
    {
        long long i = s, sum = 0;
        while(1)
        {
            sum += i;
            if(sum >= d)
            {
                printf("%lld\n", i);
                break;
            }
            i++;
        }
    }
    return 0;
}