#include<bits/stdc++.h>
using namespace std;
int main()
{
    int h1,m1,h2,m2,k;
    cin>>h1>>m1>>h2>>m2>>k;
    int a=h2-h1;
    int b=m2-m1;
    int c=(a*60+b)-k;
    cout<<c<<endl;
    exit(0);
}

#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
//#include<boost/multiprecision/cpp_int.hpp>
//#include<boost/multiprecision/cpp_dec_float.hpp>
//namespace mp=boost::multiprecision;
//#define mulint mp::cpp_int
//#define mulfloat mp::cpp_dec_float_100
using namespace std;
struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}} __init;
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
//constexpr int MOD=1000000007;
constexpr int MOD=998244353;
#define INF (1<<30)
#define LINF (lint)(1LL<<56)
#define endl "\n"
#define rep(i,n) for(lint (i)=0;(i)<(n);(i)++)
#define reprev(i,n) for(lint (i)=(n-1);(i)>=0;(i)--)
#define Flag(x) (1<<(x))
#define Flagcount(x) __builtin_popcount(x)
#define pint pair<int,int>
#define pdouble pair<double,double>
#define plint pair<lint,lint>
#define fi first
#define se second
typedef long long lint;
int dx[8]={1,1,0,-1,-1,-1,0,1};
int dy[8]={0,1,1,1,0,-1,-1,-1};
const int MAX_N=2e5+5;

int main(void){
    lint n,m,d;
    cin >> n >> m >> d;
    cout << (d?2:1)*(n-d)*(m-1)/pow(n,2) << endl;
}