#include<iostream>
#include<cstring>
using namespace std;
int data[105][205],a[3],len[105];
void Plus(int i){
    int k,l;
    for(k=i-3;k<i;k++){
        for(l=0;l<len[k];l++){
            data[i][l] += data[k][l];
            if(data[i][l]>=10){
                data[i][l+1] += data[i][l]/10
 
;
                data[i][l] %= 10;
            }
        }
        while(data[i][l]>=10){
            data[i][l+1] = data[i][l]/10;
            data[i][l] %= 10;
            l++;
        }
        if(data[i][l]>0)l++;
        len[i] = max(len[i],l);
    }
}
int main(){
    while(scanf("%d%d%d",&a[0
 
],&a[1],&a[2])==3){
        memset(data,0,sizeof data);
        memset(len,0,sizeof len);
        for(int i=0;i<3;i++){
            int j=0;
            while(a[i]>0){
                data[i][j++] = a[i]%10;
                a[i]/=10;
            }
            len[i] = j;
        }
        for(int
 
 i=3;i<100;i++){
            Plus(i);
        }
        for(int i=len[99]-1;i>-1;i--){
            printf("%d",data[99][i]);
        }
        printf("\n");
    }
    return 0;
}