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;
}