#include <bits\stdc++.h>
using namespace std;

int t;
void pr(long long a, int sz){
    int aa = a;
    while(a > 0){
        a /= 10;
        sz--;
    }
    for(int i = 0; i < sz; ++i){
        printf("0");
    }
    if(aa != 0)
    printf("%I64d", aa);
}
int main()
{
    double l, r;
    int k;
    while(cin >> l >> r >> k && k != -1)
    {
        t++;
        long long mantisa = k * log10(r);
        double cur = 0;
        for(double it = l; it <= r; ++it)
        {
            cur += pow(10.0, k * log10(it) - (double)mantisa);
        }
        while(cur >= 1)
        {
            cur /= 10;
            mantisa++;
        }
        if(r != 0){
            printf("Case ");
            pr(t, 4);
            printf(": %.6fe", cur);
            pr(mantisa, 10);
            printf("\n");
        }
        else{
            mantisa++;
            printf("Case ");
            pr(t, 4);
            printf(": %.6fe", cur);
            pr(mantisa, 10);
            printf("\n");
        }
    }
    return 0;
}