hdu 1408

#include<stdio.h>int main(){int a,i,s;double n,m;while(scanf("%lf%lf",&n,&m)!=EOF){a=n/m;if(a*m==n)a=a;elsea=a+1;s=0;for(i=1;;i++){s=s+i;if(s>=a){printf("%d\n",a+i-1);break;}}}return 0;}//注意n和m是double类型的