#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#define LL long long
#define M 2020
using namespace std;
int n,m,k,a[M],ans,x,y,tmp;
int need(int x){if(x%k==0) return x/k;return x/k+1;
}
int main(){scanf("%d%d%d",&n,&m,&k);for(int i=1;i<=m;i++){scanf("%d%d",&x,&y);a[x]++;a[y]--;}for(int i=1;i<=n+1;i++){tmp+=a[i];ans=max(ans,need(tmp));}ans=min(ans,need(m));printf("%d",ans);return 0;
}

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#define LL long long
#define M 300
using namespace std;
int n,m,f[M][M][2],x,a[M],b[M],ans;
int main(){scanf("%d%d",&n,&m);for(int i=1;i<=n;i++){scanf("%d",&a[i]);}for(int i=1;i<=n;i++){scanf("%d",&b[i]);}f[1][0][0]=a[1];f[1][0][1]=b[1];for(int i=2;i<=n;i++){for(int j=0;j<=m;j++){f[i][j][0]=f[i-1][j][0];f[i][j][1]=f[i-1][j][1];if(j>1) f[i][j][1]=max(f[i-1][j-2][0],f[i][j][1]);if(j>0) f[i][j][0]=max(f[i-1][j-1][1],f[i][j][0]);f[i][j][0]+=a[i];f[i][j][1]+=b[i];}}for(int i=0;i<=m;i++){ans=max(ans,max(f[n][i][0],f[n][i][1]));}printf("%d",ans);return 0;
}

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#define LL long long
#define M
using namespace std;
LL n,m,s[22],p[22];
bool f[22];
LL cnt(LL x){LL co=0;for(LL i=x+1;i<=n;i++){if(p[i]<p[x]) co++;}return co;
}
LL check(LL x){LL co=0;for(LL i=1;i<=n;i++){if(f[i]) continue;co++;if(co==x){f[i]=true;return i;}}return -1;//这句话毫无意义
}
int main(){s[0]=1;scanf("%lld%lld",&n,&m);memset(f,true,sizeof(f));for(LL i=1;i<=n;i++) s[i]=s[i-1]*i;for(LL i=1;i<=n;i++) scanf("%lld",&p[i]),f[i]=false;for(LL i=1;i<=n;i++){m+=cnt(i)*s[n-i];}for(LL i=1;i<=n;i++){if(i>1) printf(" ");printf("%lld",check(m/s[n-i]+1));m%=s[n-i];}return 0;
}

#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<stack>
#define LL long long
#define M 20
using namespace std;
LL n,m,p[M],f[M],l[M],r[M],c[M],cnt;
string a,b;bool isd(char x){if(x>='0'&&x<='9') return true;return false;
}
int take(char x){if(isd(x)) return x-'0';if(x=='+') return -1;if(x=='-') return -2;if(x=='*') return -3;return -4;
}
bool search(LL x){if(p[x]>=0){cnt++;if(p[x]==c[cnt]) return true;return false;}if(l[x]==0||r[x]==0) return false;if(!search(l[x])) return false;cnt++;if(p[x]!=c[cnt]) return false;if(!search(r[x])) return false;return true;
}
LL pow(LL x,LL y){if(y==0) return 1;return x*pow(x,y-1);
}
LL calc(LL x){if(p[x]>=0) return p[x];if(p[x]==-1) return calc(l[x])+calc(r[x]);if(p[x]==-2) return calc(l[x])-calc(r[x]);if(p[x]==-3) return calc(l[x])*calc(r[x]);return pow(calc(l[x]),calc(r[x]));
}
void dfs(LL x){if(x==n+1){cnt=0;if(search(1)){printf("%lld",calc(1));exit(0);}return;}for(LL i=x-1;i>0;i--){if(p[i]>=0) continue;if(l[i]==0){l[i]=x,f[x]=i;dfs(x+1);l[i]=0,f[x]=0;}else if(r[i]==0){r[i]=x,f[x]=i;dfs(x+1);r[i]=0,f[x]=0;}}
}
int main(){scanf("%lld",&n);cin>>a;cin>>b;f[1]=1;f[2]=1;for(LL i=1;i<=n;i++){p[i]=take(a[i-1]);c[i]=take(b[i-1]);}dfs(2);return 0;
}