Python

n=int(input())
s=input()
c=0
v=0
for ch in s:
    if ch=='U':
        c=c+1
    else:
        c=c-1
    if c==0 and ch=='U':
        v=v+1
print(v)

def countingValleys(steps, path):

valley_count = 0  
altitude = 0  

for step in path:
    if step == 'U':  
        altitude += 1
    else:  
        altitude -= 1

    if altitude == 0 and step == 'U':
        valley_count += 1

return valley_count

s=path level1=level2=valley=0 for i in range(len(s)): if s[i]=='U': level1+=1 else: level2+=1 if level2-level1==0: if s[i]=='U': valley+=1 return valley

s=path level1=level2=valley=0 for i in range(len(s)): if s[i]=='U': level1+=1 else: level2+=1 if level2-level1==0: if s[i]=='U': valley+=1 return valley

Here's my own PHP solution.

function countingValleys($steps, $path) {
    // Write your code here
    $altitude = 0;
    $valleys = 0;

    foreach (str_split($path) as $step) {

        if ($altitude == 0 && $step == 'D') {
            $valleys++;
        }

        if ($step == 'U') {
            $altitude++;
        } else {
            $altitude--;
        }
    }

    return $valleys;
}