#include <fstream>
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sstream>
#include <map>
#include <set>
#include <vector>
#include <cmath>
#include <queue>
#include <random>

using namespace std;

#define min(a,b) ((a)<(b) ? (a):(b))
#define max(a,b) ((a)>(b) ? (a):(b))

long long maxd(long long a,long long b){
    if(a>=b){
        return a;
    }
    return b;
}
long long mind(long long a,long long b){
    if(a<=b){
        return a;
    }
    return b;
}

long long gcd(long long a, long long b){
    if(a<b){
        swap(a,b);
    }
    while(b){
        long long r = a%b;
        a=b;
        b=r;
    }
    return a;
}

long long lcm(long long a, long long b){
    return (a*b)/gcd(a,b);
}

int isPrim(int a){
    if(a==1){
        return 0;
    }
    for(int i=2;i<=(a+1)/2;i++){
        if(a%i==0){
            return 0;
        }
    }
    return 1;
}

long long mod_pow(long long x, long long n, long long mod){
    //xのn乗を計算するのにn乗を2進表記にして計算
    //x^22 = x^16 + x^4 + x^2
    long long ret=1;
    while(n>0){
        if(n%2==1){
            ret=(ret*x)%mod;//答えに付加
        }
        x=(x*x)%mod;//2乗
        n=n/2;
    }
    return ret;
}


struct XX{
    long long i;
    long long v;
    long long left;
    long long right;
};

class xxIntu {
public:
    bool operator()(const XX& riLeft, const XX& riRight) const {
        //第2条件
        if((riLeft.v) == (riRight.v)){
            return riLeft.i < riRight.i;//<:昇順(小さいものから順番)、>:降順(大きいものから順番)
        }
        //第1条件
        return (riLeft.v) < (riRight.v);
    }
};

class xxIntk {
public:
    bool operator()(const XX& riLeft, const XX& riRight) const {
        //第2条件
        if((max(riLeft.right,riLeft.left)) == (max(riRight.right,riRight.left))){
            return (riLeft.v) < (riRight.v);
        }
        //第1条件
        return (min(riLeft.right,riLeft.left)) < (min(riRight.right,riRight.left));
    }
};


int ppar[200001];
int rrank[200001];

void init(int n){
    for(int i=1;i<=n;i++){
        ppar[i]=i;
        rrank[i]=0;
    }
}

int find(int x){
    if(ppar[x]==x){
        return x;
    }else{
        return ppar[x]=find(ppar[x]);
    }
}

void unite(int x,int y){
    x=find(x);
    y=find(y);
    if(x==y){
        return;
    }
    if(rrank[x]<rrank[y]){
        ppar[x]=ppar[y];
    }else{
        ppar[y]=x;
        if(rrank[x]==rrank[y]){
            rrank[x]++;
        }
    }
}
bool same(int x,int y){
    return find(x)==find(y);
}

//kruskal
struct edge{
    int u;
    int v;
    int cost;
};

bool comp(edge& e1,edge& e2){
    return e1.cost < e2.cost;
}

edge es[2000];
int V,E;
int ans=0;
int kruskal(){
    sort(es,es+E,comp);
    init(V);
    int res = 0;
    for(int i=0;i<E;i++){
        edge e = es[i];
        if(!same(e.u,e.v)){
            unite(e.u,e.v);
            res+=e.cost;
            ans++;
        }
    }
    return res;
}


int main(int argc, const char * argv[])
{
    //std::ios::sync_with_stdio(false);
    //scanf("%s",S);
    //scanf("%d",&N);
    //sscanf(tmp.c_str(),"%dd%d%d",&time[i], &dice[i], &z[i]);
    //getline(cin, target);
    //cin >> x >> y;
    //テスト用
    //ifstream ifs( "1_06.txt" );
    //ifs >> a;
    //ここから
    
    int A,B,C;
    cin >> A >> B >> C;
    int a=A;
    int b=B;
    int c=C;
    int ans=0;
    while(true){
        
        if(a%2==1 || b%2==1 || c%2==1){
            cout << ans << endl;
            return 0;
        }
        int tmpa=b/2+c/2;
        int tmpb=a/2+c/2;
        int tmpc=a/2+b/2;
        a=tmpa;
        b=tmpb;
        c=tmpc;
        ans++;
        
        if(a==A && b==B && c==C){
            cout << -1 << endl;
            return 0;
        }
    }

    
    //ここまで
    //cout << "ans" << endl;改行含む
    //printf("%.0f\n",ans);//小数点以下表示なし
    //printf("%.7f\n",p);
    //printf("%f\n",pow(2,ans.size()));
    
    return 0;
}


Measured memory_bytes: 256