13 lines
195 B
C
13 lines
195 B
C
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#include <stdio.h>
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int main(void){
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unsigned long long n,m,i;
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double sum = 0.0;
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scanf("%llu %llu",&n,&m);
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for(i = n; i <= m; i++){
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sum += 1.0/(i*i);
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}
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printf("%.5lf\n",sum);
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return 0;
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}
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