#include<cstdio>
//除基取余法 
const int M = 30;int main(){long long a,b,c;int D,ans[M+2];scanf("%lld%lld%d",&a,&b,&D);c=a+b;int num=0;do{ans[num++]=c%D;c = c/D;}while(c!=0);for(int i=num-1;i>=0;i--){printf("%d",ans[i]);}return 0;
}