29 lines
415 B
C++
29 lines
415 B
C++
#include <iostream>
|
|
using namespace std;
|
|
int main(){
|
|
int l,m;
|
|
int start,end;
|
|
cin>>l>>m;
|
|
int a[l+1];
|
|
for(int i=0;i<=l;i++){
|
|
a[i]=1;
|
|
}
|
|
for(int i=0;i<m;i++){
|
|
cin>>start>>end;
|
|
//cout<<"yes"<<endl;
|
|
for(int j=start;j<=end;j++){
|
|
a[j]=0;
|
|
//cout<<j<<" set 0"<<endl;
|
|
}
|
|
}
|
|
int js=0;
|
|
for(int i=0;i<=l;i++){
|
|
//cout<<i<<" "<<a[i]<<endl;
|
|
if(a[i]==1) {
|
|
js++;
|
|
}
|
|
}
|
|
cout<<js<<endl;
|
|
return 0;
|
|
}
|