program SMAX;

const

MAXN = 10000000;

var

n, i: longint;

a: int64;

curSum, maxSum: int64;

f: text;

begin

assign(f, 'SMAX.INP');

reset(f);

readln(f, n);

curSum := 0;

maxSum := -1000000000000000000; { rất nhỏ }

for i := 1 to n do

begin

read(f, a);

if curSum + a > a then

curSum := curSum + a

else

curSum := a;

if curSum > maxSum then

maxSum := curSum;

end;

close(f);

assign(f, 'SMAX.OUT');

rewrite(f);

writeln(f, maxSum);

close(f);

end.

#include <bits/stdc++.h>

using namespace std;

long long n,i,x,t,dem;

int main()

{

cin>>n;

t=0;

dem=0;

for (i=1; i<=n; i++)

{

cin>>x;

if (x<5) 

{

t=t+x;

dem++;

}

}

cout<<t<<" "<<dem;

return 0;

}

#include <bits/stdc++.h>

using namespace std;

long long i,n,x,dem;

int main()

{

cin>>n;

dem=0;

for (i=1; i<=n; i++)

{

cin>>x;

if (x!=0) dem++;

}

cout<<dem;

return 0;

}

#include <bits/stdc++.h>

using namespace std;

long long n,i,x,dem;

int main()

{

cin>>n;

dem=0;

for (i=1; i<=n; i++)

{

cin>>x;

if (x==0) dem++;

}

cout<<dem;

return 0;

}

a: #incldue <bits/stdc++.h>

using namespace std;

long long i,n,x,t;

int main()

{

cin>>n;

t=0;

for (i=1; i<=n; i++)

{

cin>>x;

if (x>0) t=t+x;

}

cout<<t;

return 0;

}

phần a

phần b

d: 

#include <bits/stdc++.h>

using namespace std;

long long i,n,s;

int main()

{

cin>>n;

s=0;

for (i=1; i<=n; i++)

s=s+i;

cout<<s;

return 0;

}