// Slower C++ solution:
#include <bits/stdc++.h>



using namespace std;



typedef long long               ll;

typedef long double             ld;



#define min3(a, b, c)           min((a), min((b), (c)))

#define max3(a, b, c)           max((a), max((b), (c)))

#define lcm(a,b)                (a / __gcd(a,b) ) *b

#define gcd(a,b)                __gcd(a,b)

#define dist(x1,y1,x2,y2)       sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1))

#define distl(x1,y1,x2,y2)      sqrtl((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1))

#define sqr(a)                  ((a)*(a))

#define urs(r...)               typename decay<decltype(r)>::type

#define FOR(i,a,b)              for(urs(b) i=a;i<b;i++)

#define ROF(i,a,b)              for(urs(b) i=a;i>=b;i--)

#define REP(a,b)                for(urs(b) i=a;i<b;i++)

#define pb                      push_back

#define mk                      make_pair

#define ff                      first

#define ss                      second

#define lb                      lower_bound

#define ub                      upper_bound

#define all(a)                  a.begin(),a.end()

#define vi                      vector <int> 

#define pi                      pair <int, int> 

#define SORT(v)                 sort(v.begin(), v.end());

#define FASTIO                  ios_base::sync_with_stdio(0);cin.tie(NULL);

#define PI                      acos(-1.0)

#define nl                      "\n"

#define watch(x)                cerr << "\n" << (#x) << " is " << (x) << endl;



#define pii pair<int, int>

#define pll pair<long long, long long>

#define pld pair<long double, long double>



const int MOD = 1e9 + 7;



ll fast_pow (ll n, ll p)

{

    ll res=1;

    while (p>0)

    {

        if (p&1)

            res = res * n;

        p = p>>1;

        n = n * n;

    }

    return res;

}



ll BMod(ll B,ll P,ll M)

{

    ll R=1;

    B=B%M;

    while(P)

    {

        if(P&1)

            R=(R*B)%M;

        P >>= 1;

        B=(B*B)%M;

    }

    return R;

}



ll invMOD(ll num,ll M)

{

    return BMod(num,M-2,M);

}



//use this, if overflow happens

uint64_t mulmod(uint64_t a, uint64_t b, uint64_t m)

{

    if (a > b)

        swap (a, b);



    uint64_t res = 0;

    uint64_t temp_b;



    if (b >= m)

    {

        if (m > UINT64_MAX / 2u)

            b -= m;

        else

            b %= m;

    }



    while (a != 0)

    {

        if (a & 1)

        {    

            if (b >= m - res)

                res -= m;

            res += b;

        }

        a >>= 1;



        temp_b = b;

        if (b >= m - b)

            temp_b -= m;

        b += temp_b;

    }

    return res;

}



#ifdef Sieve

const int pSz = 50005;

bool np[pSz + 10]; vi prime; int prime_size;

void sieve(){np[0] = np[1] = 1;prime.pb(2);

for(ll i = 4; i <= pSz; i+=2) np[i] = 1;

for(ll i = 3; i <= pSz; i+=2){if(!np[i]){prime.pb(i);

for(ll j = i * i; j <= pSz; j += (i << 1)) np[j] = 1;}}prime_size = prime.size();}

#endif



#ifdef Combi

const int nSz = 2000006;

ll F[nSz + 1], tMod = MOD;

void Factorial(){ F[0] = 1; for(int i = 1; i <= nSz; i++) F[i] = (F[i - 1] * i) % tMod; }

inline ll nCr(int n, int r) { if(n < r) return 0; return (F[n] * invMOD((F[n - r] * F[r]) % tMod, tMod)) % tMod; }

 

#endif

 

#ifdef Z_Algo

void zAlgo(char *s, int *z){

    int L, R, sz; sz = strlen(s); z[0] = L = R = 0;

    FOR(i, 1, sz) { z[i] = 0; if(i <= R) z[i] = min(z[i - L], R - i + 1); 

    while(i + z[i] < sz && s[i + z[i]] == s[z[i]]) z[i]++; if(i + z[i] - 1 > R) L = i, R = i + z[i] - 1; }

}void zAlgo(string &s, int *z){

    int L, R, sz; sz = s.size(); z[0] = L = R = 0;

    FOR(i, 1, sz) { z[i] = 0; if(i <= R) z[i] = min(z[i - L], R - i + 1); 

    while(i + z[i] < sz && s[i + z[i]] == s[z[i]]) z[i]++; if(i + z[i] - 1 > R) L = i, R = i + z[i] - 1; }

}void zAlgo(int *s, int *z, int n){

    int L, R, sz; sz = n; z[0] = L = R = 0;

    FOR(i, 1, sz) { z[i] = 0; if(i <= R) z[i] = min(z[i - L], R - i + 1); 

    while(i + z[i] < sz && s[i + z[i]] == s[z[i]]) z[i]++; if(i + z[i] - 1 > R) L = i, R = i + z[i] - 1; }

}

#endif



//-------------------------DEBUGGING-STUFF------------------------------//

#ifdef __beyond_TLE__

void __print(int x) {cerr << x;}

void __print(long x) {cerr << x;}

void __print(long long x) {cerr << x;}

void __print(unsigned x) {cerr << x;}

void __print(unsigned long x) {cerr << x;}

void __print(unsigned long long x) {cerr << x;}

void __print(float x) {cerr << x;}

void __print(double x) {cerr << x;}

void __print(long double x) {cerr << x;}

void __print(char x) {cerr << '\'' << x << '\'';}

void __print(const char *x) {cerr << '\"' << x << '\"';}

void __print(const string &x) {cerr << '\"' << x << '\"';}

void __print(bool x) {cerr << (x ? "true" : "false");}



template<typename T, typename V>

void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}

template<typename T>

void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}

void _print() {cerr << "]\n";}

template <typename T, typename... V>

void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}

#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)

#else

#define debug(x...)

#endif

//---------------------------END---------------------------------//



void __INIT__()

{

    #ifdef __beyond_TLE__

        freopen("input.txt", "r", stdin);

        freopen("output.txt", "w", stdout);

        #define cerr if(true)cerr

        freopen("Eroor.txt", "w", stderr);

    #endif



    #ifndef __beyond_TLE__

        #define cerr if(false)cerr

    #endif

}



int main()

{

    FASTIO

    __INIT__();



    ll n, a, b;

    cin >> n >> a >> b;



    if (n==1)

    {

        if (a==b)

            cout << 1 <<endl;

        else

            cout << 0 <<endl;

    }

    else

    {

        if (a > b)

            cout << 0 <<endl;

        else

            cout << (((b-a)*(n-2))+1) <<endl;

    }



    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.313949046409202x):
#include <cstdio>

#include <cstring>

typedef long long ll;

int main(){

    int n,a,b;scanf("%d%d%d",&n,&a,&b);

    ll l = 1LL*a*(n-1) + b,r = 1LL*b*(n-1) + a;

    if(l > r) {puts("0");return 0;}

    else printf("%lld\n",(r-l+1));

    return 0;

}