cf 697 A

                  

链接：http://codeforces.com/problemset/problem/697/A

#include <bits/stdc++.h>using namespace std;int main(){    int n,m,k;    scanf("%d%d%d",&n,&m,&k);    if(k<n)printf("NO\n");    else if(k==n)printf("YES\n");    else    {        if(((k-n)%m==0||(k-n-1)%m==0)&&k>=n+m)            printf("YES\n");        else            printf("NO\n");    }        return 0;}