s=list(input())
n=len(s)
l=[]
y=10**6
for i in range(n-3):
    if s[i]=="p" and s[i+1]=="a" and s[i+2]=="i" and s[i+3]=="n":
        y=i
        break

if y==10**6:
    exit(print(-1))


ans=0

for i in range(y-3):
    if s[i]=="p" and s[i+1]=="o" and s[i+2]=="n":
        ans+=1

if ans<=1:
    print(-1)

else:
    print(ans)