2. Bit Toggle

#include <stdio.h>

int toggleFifthBit(int n) {
    // Write your code here
    n ^= (1 << 5);
    return n;
}

int main() {
    int n;
    scanf("%d", &n);
    printf("%d", toggleFifthBit(n));
    return 0;
}

Toggling the fifth bit is simply applying the XOR operator bitwise to the 5th bit with the bit value of 1. Truth table of XOR that matters:
0 XOR 1 = 1
1 XOR 1 = 0