#include <stdio.h>
 
int main(void) {
    double p_no_match = 1.0; // Probability that NO ONE shares a birthday
    int i = 0;
 
    // We want the probability of a match (1 - p_no_match) to be >= 0.5
    // Which is the same as p_no_match being <= 0.5
    while (p_no_match > 0.5) {
        i++;
        // Multiply by (remaining days / total days)
        p_no_match *= (365.0 - i + 1) / 365.0;
    }
 
    printf("Number of people needed: %d\n", i);
    return 0;
}

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