#include <stdio.h>
int main()
{
    int num1, num2, num3;

    printf("Enter three numbers: ");
    scanf("%d %d %d", &num1, &num2, &num3);

    if( num1 >= num3 && num1 >= num3 ){
    
        printf("%d is the largest number.", num1);
    }
    
    else if( num2 >= num1 && num2 >= num3 ){
        printf("%d is the largest number.", num2);
    } 
    
    else if( num3 >= num1 && num3 >= num2 ){
    	printf("%d is the largest number.", num3);
    }        

    return 0;
}

Result

 

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