Forgotten measurements

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef uint64_t u64;

int main() {
    string input;
    cin >> input;
    u64 out = 1;
    u64 i = 0;
    while (i < input.size()) {
        if (input[i] == 'U' && input[i+2]=='D') {
            out++;
            input.erase(i, 4);
            i -= 2;
        }
        if (input[i] == 'D' && input[i+2]=='U') {
            out++;
            input.erase(i, 4);
            i -= 2;
        }
        if (input[i] == 'L' && input[i+2]=='R') {
            out++;
            input.erase(i, 4);
            i -= 2;
        }
        if (input[i] == 'R' && input[i+2]=='L') {
            out++;
            input.erase(i, 4);
            i -= 2;
        }
        i++;
    }
    cout << out;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER