#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;

int qiujie(int a,int b,int c)
{
    int x;
    for(x=0; x<=c/a; x++) //枚举x可取的所有可能
    {
        if((c-a*x)%b==0)  //判断是否存在正整数y
        {
            return 1;
        }
    }
    return 0;
}
int main()
{
    int a,b,c,i,j;
    char s1[16],s2[16],ch,cj;
    while(cin>>s1>>ch>>s2>>cj>>c)
    {
        a=b=0;
        for(i=0; i<strlen(s1)-1; i++)
        {
            if(s1[i]!='x')
            {
                a+=s1[i]-'0';
                if(s1[i+1]!='x')
                    a*=10;
            }
            /* a*=10;
              a+=s1[i]-'0';*/

        }
        for(j=0; j<strlen(s2)-1; j++)
        {
            if(s2[j]!='y')
            {
                b+=s2[j]-'0';
                if(s2[j+1]!='y')
                    b*=10;
            }
            /*  b*=10;
              b+=s2[j]-'0';*/
        }
        if(s1[0]=='x')a=1;
        if(s2[0]=='y')b=1;
        if(qiujie(a,b,c)==1)
            printf("Yes.\n\n");
        else
            printf("No.\n\n");

    }
    return 0;
}