UVa 11636: Hello world! Soluiton.cpp

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

int main(){


    int n,i=1 ,sum;

    while(scanf("%d",&n)){
        sum = 0;
        if(n<0)
        break;

        sum = ceil(log2(n));
        printf("Case %d: %d\n",i++,sum);


    }

    return 0;
}