A. Dasha and Stairs time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output On her way to programming school tiger Dasha faced her first test — a huge staircase!
The steps were numbered from one to infinity. As we know, tigers are very fond of all striped things, it is possible that it has something to do with their color. So on some interval of her way she calculated two values — the number of steps with even and odd numbers.
You need to check whether there is an interval of steps from the l-th to the r-th (1 ≤ l ≤ r), for which values that Dasha has found are correct.
Input In the only line you are given two integers a, b (0 ≤ a, b ≤ 100) — the number of even and odd steps, accordingly.
Output In the only line print “YES”, if the interval of steps described above exists, and “NO” otherwise.
Examples input 2 3 output YES input 3 1 output NO Note In the first example one of suitable intervals is from 1 to 5. The interval contains two even steps — 2 and 4, and three odd: 1, 3 and 5. 分析 只要a,b不同时为0,则abs(a-b)<=1.
#include<cstdio> #include<cmath> using namespace std; int main(){ int a,b; scanf("%d%d",&a,&b); int c=a-b; if( (a!=0||b!=0) &&(abs(a-b)<=1) ) printf("YES\n"); else printf("NO\n"); return 0; }