#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int s=0,n=1; /* while(s<=1000){ s+=n; //cout<<n<<" "<<s<<endl; n++; } cout<<n-1<<endl; */ do{ n++; s+=n; }while(s<=1000); cout<<n<<endl; return 0; }