hud 6033

题意：给出m,问2的m次方-1==10的k次方（最接近），求k

思路：可以看成2^m=10^k，取个log,k=m*log2/log10

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(){
    int n;
    int kk=1;
    while(scanf("%d",&n)!=EOF){
        printf("Case #%d: ",kk++);
        int x=log(2)/log(10)*n;
        printf("%d\n",x);
    }
    return 0;
}