http://codeforces.com/contest/92
A
1 #include<iostream> 2 using namespace std; 3 #define lson l,mid,rt<<1 4 #define rson mid+1,r,rt<<1|1 5 #define sqr(x) ((x)*(x)) 6 #define maxn 100005 7 typedef long long ll; 8 typedef unsigned long long ull; 9 const ull MOD=257; 10 /*#ifndef ONLINE_JUDGE 11 freopen("1.txt","r",stdin); 12 #endif */ 13 14 15 16 int main(){ 17 #ifndef ONLINE_JUDGE 18 // freopen("1.txt","r",stdin); 19 #endif 20 std::ios::sync_with_stdio(false); 21 int n,m; 22 cin>>n>>m; 23 int i=0; 24 while(i+1<=m){ 25 m-=i+1; 26 i++; 27 if(i==n) i%=n; 28 } 29 cout<<m<<endl; 30 }