clear all
clc

n = input('enter a positive integer: ');
t1 = 0; t2=0; t3=0;
for i=1:1:n
    t1=t1+i;
end

for i=1:2:n
    t2=t2+i; 
end

for i=2:2:n
    t3=t3+i;
end

fprintf('\n The sum of integers from 1 to %d: %d \n',n,t1)
fprintf('\n The sum of odd integers from 1 to %d: %d \n',n,t2)
fprintf('\n The sum of even integers from 1 to %d: %d \n',n,t3)