Excel Sheet Column
a=int(input())
p="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
s=""
while a>0:
r=a%26
if r==0:
s+='Z'
a=(a//26)-1
else:
s+=p[r-1]
a//=26
for i in range(len(s)-1,-1,-1):
print(s[i],end="")
PRIMES IN RANGE
def prime(n):
for i in range(2,int(n**0.5)+1):
if(n%i==0):
return 0
else:
if(n!=0 and n!=1):
return 1
m=int(input())
n=int(input())
c=0
for i in range(m,n+1):
if(prime(i)):
c+=1
print(c)
Find sum of natural numbers
a=int(input())
print((a*(a+1))//2)
Counting Pretty numbers
t=int(input())
for i in range(t):
a,b=map(int,input().split())
count=0
for i in range(a,b+1):
if i%10 in [2,3,9]:
count+=1
print(count)
Find sum of series
a=int(input())
sum=0.0
for i in range(1,a+1):
sum+=(1/i)
print(format(sum,'.2f'))
